Facebook is working with law enforcement following the gun massacre at a Walmart in El Paso, Texas, a spokesperson for the social media giant said, according to reports.

The social media giant has removed Facebook and Instagram accounts under the suspect’s name.

“Our thoughts are with the victims and their families. Content that praises, supports or represents the shooting or anyone responsible violates our Community Standards and we will continue to remove as soon as we identify it”, a Facebook spokesperson said. 

Two federal law enforcement sources said that investigators are reportedly reviewing a "manifesto" posted days before the shooting that may identify a motive.

The online posting was believed to be written by the shooter, Patrick Crusius, but it has not been proven, according to reports.Texas Attorney General Ken Paxton said later on Saturday that at least 15 people had been shot and killed in a shopping center shooting at a Walmart in the city of El Paso.