TALUQAN, Afghanistan, April 19 (Xinhua) — About 62 Afghan girl students were hospitalized Tuesday due to a possible gas poisoning in the country’s northern province of Takhar, police said.

“Up to 62 students of the Sar-e-Rustaq Girl High School in Rustaq District were shifted to district hospital after they showed symptoms of vomiting, and several had fallen unconscious. Most of the students were discharged shortly after receiving treatment,” Abdul Asir Khalil, provincial police spokesman, told Xinhua.

An investigation has been initiated to find the facts behind the incident, he said.

No group or individual has claimed the responsibility for the incident so far. Radical Islamic groups and anti-government militants had in the past been blamed for such gas attacks.

The conflict-related violence resulted in the partial or complete closure of nearly 400 schools across the country last year, affecting more than 139,000 students and 600 teachers, according to a report released by the UN mission in the country on Monday.

Up to 11 education personnel were killed, 15 injured and 49 others were abducted by militants in different places in the country in 2015, the report said.