(01 of19)
Open Image ModalSouth Korean marine LVT-7 landing craft sail to shores through smoke screens during the U.S.-South Korea joint military exercises called Ssangyong, part of the Foal Eagle military exercises, in Pohang, South Korea, Monday, March 31, 2014. South Korea said North Korea has announced plans to conduct live-fire drills near the rivals' disputed western sea boundary. The planned drills Monday come after an increase in threatening rhetoric from Pyongyang and a series of rocket and ballistic missile launches in an apparent protest against the annual military exercises by Seoul and Washington.
(02 of19)
Open Image ModalSouth Korean Marine amphibious assault vehicles land on the seashore during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. North Korea announced a live-fire drill on March 31 near its disputed maritime border with South Korea, further ratcheting up tensions a day after threatening a 'new form' of nuclear test. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(03 of19)
Open Image ModalA South Korean Marine sits in an amphibious assault vehicle during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. Meanwhile, the two Koreas traded hundreds of rounds of live artillery fire across their disputed maritime border, forcing South Korean islanders to take shelter a day after the North drove up tensions by threatening a new nuclear test. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(04 of19)
Open Image ModalSouth Korean Marine amphibious assault vehicles land on the seashore during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. North Korea announced a live-fire drill on March 31 near its disputed maritime border with South Korea, further ratcheting up tensions a day after threatening a 'new form' of nuclear test. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(05 of19)
Open Image ModalLunch trays for students are left on tables of a cafeteria after students were evacuated to a shelter at a school on Yeonpyeong island, South Korea, near the West Sea border with North Korea, Monday, March 31, 2014. North and South Korea fired artillery shells into each other's waters Monday, a flare-up of animosity between the rivals that forced residents of five front-line South Korean islands to evacuate to shelters, South Korean officials said. (credit:AP)
(06 of19)
Open Image ModalUS Marines take a position during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. North and South Korea traded fire across their disputed maritime border on March 31, with the South's military saying it had responded to shells landing in its waters from a North live-fire drill. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(07 of19)
Open Image ModalSouth Korean Marines exit an amphibious assault vehicle during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. Meanwhile, the two Koreas traded hundreds of rounds of live artillery fire across their disputed maritime border, forcing South Korean islanders to take shelter a day after the North drove up tensions by threatening a new nuclear test. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(08 of19)
Open Image ModalSouth Korean anti-war activists march near an amphibious assault vehicle during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. North and South Korea traded fire across their disputed maritime border on March 31, with the South's military saying it had responded to shells landing in its waters from a North live-fire drill. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(09 of19)
Open Image ModalUS Marines take a position as South Korean policemen stand guard to block protestors during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. North and South Korea traded fire across their disputed maritime border on March 31, with the South's military saying it had responded to shells landing in its waters from a North live-fire drill. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(10 of19)
Open Image ModalUS Marines get out from an amphibious assault vehicle during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. North Korea announced a live-fire drill on March 31 near its disputed maritime border with South Korea, further ratcheting up tensions a day after threatening a 'new form' of nuclear test. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(11 of19)
Open Image ModalSouth Korean (R) and US (L) Marines gesture to a point during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. North Korea announced a live-fire drill on March 31 near its disputed maritime border with South Korea, further ratcheting up tensions a day after threatening a 'new form' of nuclear test. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(12 of19)
Open Image ModalUS Marines take a positon during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. North Korea announced a live-fire drill on March 31 near its disputed maritime border with South Korea, further ratcheting up tensions a day after threatening a 'new form' of nuclear test. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(13 of19)
Open Image ModalUS Marines sit in an amphibious assault vehicle during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. North Korea announced a live-fire drill on March 31 near its disputed maritime border with South Korea, further ratcheting up tensions a day after threatening a 'new form' of nuclear test. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(14 of19)
Open Image ModalSouth Korean anti-war activists march near a beach as policemen stand guard during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. North and South Korea traded fire across their disputed maritime border on March 31, with the South's military saying it had responded to shells landing in its waters from a North live-fire drill. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(15 of19)
Open Image ModalA South Korean Marine stands on a beach as amphibious assault vehicles (in background) approach the seashore during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. Meanwhile, the two Koreas traded hundreds of rounds of live artillery fire across their disputed maritime border, forcing South Korean islanders to take shelter a day after the North drove up tensions by threatening a new nuclear test. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(16 of19)
Open Image ModalA US Marine takes a position during a joint landing operation by US and South Korean Marines in Pohang, 270 kms southeast of Seoul, on March 31, 2014. North and South Korea traded fire across their disputed maritime border on March 31, with the South's military saying it had responded to shells landing in its waters from a North live-fire drill. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images) (credit:Getty Images)
(17 of19)
Open Image ModalIn this photo provided by the Ongjin County, residents of Baengnyeong Island evacuate their homes to a shelter on the island, South Korea, near the West Sea border with North Korea, Monday, March 31, 2014. North and South Korea fired artillery shells into each other's waters Monday, a flare-up of animosity between the rivals that forced residents of five front-line South Korean islands to evacuate to shelters, South Korean officials said. (credit:AP)
(18 of19)
Open Image ModalA man watches a television news program reporting about North Korea's plan to conduct live-fire drills, at a Seoul train station in Seoul, South Korea, Monday, March 31, 2014. South Korea said North Korea has announced plans to conduct live-fire drills near the rivals' disputed western sea boundary. Seoul's Defense Ministry said North Korea says it will conduct firing drills in seven areas north of the sea boundary. Seoul responded that it will strongly react if provoked. The writing reads "North, Firing drills in seven areas western sea." (credit:AP)
(19 of19)
Open Image ModalIn this photo provided by the Ongjin County, residents of Baengnyeong Island watch a big screen showing a TV news report about North Korea's firing drills as they evacuate to a shelter on the the island, South Korea, near the West Sea border with North Korea, Monday, March 31, 2014. North and South Korea fired artillery shells into each other's waters Monday, a flare-up of animosity between the rivals that forced residents of five front-line South Korean islands to evacuate to shelters, South Korean officials said. (credit:AP)