02/10/2015 05:31 BST | Updated 02/10/2015 05:59 BST

Oregon Shooting: Police Investigate If Gunman Posted Warning On 4chan Before Killing 9

Federal law officials investigating the Oregon college massacre are scrutinising a 4chan thread to determine if it is linked to the gunman.

Chris Harper-Mercer killed at least nine people before being fatally shot in a stand-off with police on Thursday.

Ahead of the shooting, a posting on the message board included a photo of a crudely drawn frog used regularly in Internet memes with a gun and warned other users not to go to school on Thursday in the Northwest.

pepe frog oregon shooting

Federal law enforcement officers are examining these messages

It said: “Some of you guys are alright. Don’t go to school tomorrow if you are in the northwest. Happening thread will be posted tomorrow morning.

“So long space robots.”

chris harpermercer

Gunman Chris Harper-Mercer was killed

The messages that followed spoke of mass shootings, with some egging on and even offering tips to the original poster. The full archived thread can be read here.

It was unclear if the messages were tied to the shooting because of the anonymous and sprawling nature of the site.

oregon shooting

Relatives and friends comfort each other in the wake of the shooting

As The Verge points out: “4chan has become a popular place for internet trolls who enjoy riling up the community with hoax statements.”

What's more, The Daily Dot reports a 4chan forum then tried to retrospectively frame one of its own users for the mass shooting.

But attempts to finger user “Eggman” were unsuccessful when NBC was able to prove he was actually alive and had reached out to the channel.

Gunman Harper-Mercer, who was reportedly born in the UK, had social media profiles featuring content supporting the IRA and apparently demanded to know his victims' religious beliefs before opening fire at Umpqua Community College in Roseburg, Oregon.

It is the 45th school shooting in the US this year.

Photo gallery Umpqua Community College Shooting See Gallery