MOSCOW -- A Moscow high school was evacuated after a 16-year-old student brought a knife into the building and threatened to cut himself, authorities said.
Police said teachers and students were evacuated from Secondary School No. 1359 in the capital on December 6.
The principal later said a relative helped get the boy to surrender the knife, state-run news agency RIA Novosti reported. There were no reports of injuries.
Moscow Mayor Sergei Sobyanin tweeted earlier that police psychiatrists were "working with" the 10th grader after he was isolated from other students.
There have been several incidents this year in which students have brought weapons to educational institutions, in some cases carrying out attacks.
On November 12, a 14-year-old boy in the Volgograd region brought an ax, several knives, and a gas canister to his school, and was hospitalized for a day after he swallowed rat poison, authorities said. Nobody else was hurt.
On October 17, an 18-year-old student killed 20 people and wounded dozens in a gun-and-bomb attack at a technical college in Kerch, in Russian-controlled Crimea, before killing himself.
On December 4, the Russian parliament's lower house passed a bill banning so-called "online Columbine communities" that lawmakers say encourage violence among schoolchildren.
Columbine is a high school in the U.S. state of Colorado where two students staged an attack in 1999, killing 12 fellow students and a teacher before fatally shooting themselves.