LOS ANGELES (AFP) - A student opened fire at a US school Friday, injuring as many as six people before killing himself, the Seattle Times reported, citing law enforcement sources.

Live TV pictures showed swarms of police and emergency workers descending on the Marysville-Pilchuck High School in the western state of Washington.

The shooting occurred in the school cafeteria, according to multiple reports.

"I was eating... I hear four gunshots and it was behind me. I saw a gun pointed at a table... then I ran out of the exit," one student in the cafeteria, named only as Alex, told KIRO TV news.

Television footage also showed schoolchildren coming out of the sprawling campus in Marysville, 55 km north of Seattle.

The Marysville School District said on its website: "The Marysville-Pilchuck High School is currently in lockdown due to an emergency situation. Police and emergency services have responded."