A truck driver who caused an accident in Vietnam confessed he had taken methamphetamine days prior to the accident. Luong Van Tam, 28, fled the scene after causing the accident on a highway in Hai Duong province that killed at least eight and injured eight others on January 21, VN Express reported.

Authorities performed a drug test on him after he surrendered, which tested positive for methamphetamine on the same night. He now faces charges of “violating road traffic regulations that cause serious consequences” – which is punishable by a maximum penalty of 15 years in jail.

Tam told authorities that he dozed off at the wheel before he drove into the motorbike lane and ran over the victims. The Department of Transport in Hanoi has revoked the license of the company that hired him in the aftermath of the accident.

Deputy Prime Minister Truong Hoa Binh also ordered an immediate investigation into the accident and demanded a report be handed in before the Lunar New Year holidays.

Drug use is not uncommon among truck drivers in Vietnam. A study conducted by the Ministry of Transport in 2014 had 526 out of 136,000 drivers testing positive for drugs.

Read: Nine killed when truck hits crowd on Vietnam highway