British and US forces have stormed an Italian merchant ship hijacked by Somali pirates, rescuing the crew.

The Ministry of Defence (MoD) in London confirmed the pirates surrender on Tuesday morning after an operation aided by the Royal Navy.

“We can confirm that late this morning the RFA Fort Victoria, currently on Nato counter piracy operations east of Suez, responded to calls to assist a pirated Italian merchant ship, the MV Montecristo, along with an American Navy frigate," the ministry said.

"Due to the presence of the warships, 11 suspected pirates on board the pirated vessel surrendered without force. A Royal Naval boarding team carried out a compliant boarding of the vessel and the suspected pirates are being detained.”

The Montecristo was hijacked by pirates 620 miles off the coast of Somalia on Monday and its 23-man crew were taken hostage.

A Nato spokesperson told the Sun that the USS De Wert was the first ship in the area while the boarding team assembled on the British ship Fort Victoria.

"Nato forces got on board and the pirates surrendered immediately. No one on board from the team, the crew or the pirates were injured," they said.

Despite today's rescue mission, pirate attacks appear to be on the increase.

The International Maritime Bureau (IMB) has reported that the number of attacks on the world’s seas totalled 266 in the first six months of 2011, up from 196 incidents in the same period last year.

More than 60 per cent of the attacks were by Somali pirates.

A report published in July by the IMB showed that Somali pirates made 163 attacks in 2011 year up from 100 in the first six months of 2010.

The increased presence of international naval forces did manage to prevent the pirates from hijacking as many ships however, with just 21 taken in the first half of 2011 compared with 27 in the same period last year.