BEIJING — A former doctor armed with a large knife rampaged outside an elementary school in eastern China, stabbing eight young children to death and wounding five others Tuesday, a local official and a state news agency said.

The assailant was arrested after the early morning attack, launched as students were arriving for school, Xinhua News Agency said. His rampage was finally stopped by passers-by and school security guards, Xinhua said, citing Wu Jiachong, the owner of a nearby shop.

The attacker, Zheng Minsheng, 41, worked as a doctor in a community clinic before resigning last June, Xinhua said, citing Huang Zhongping, spokesman for the Nanping city public security bureau.

Zheng was known to have a history of mental illness, said a man surnamed Wu in the Nanping city government office, who would not give his full name as is common among Chinese officials. Eight children from Nanping City Experimental Elementary School were killed, and five were being treated at a hospital, Wu said. Six died at the scene.

The victims' ages were not known, but Chinese elementary schools typically have students ages 6 to 12.

The school was closed and students were sent home for the day.