An overcrowded bus carrying Afghans expelled from Iran crashed in western Afghanistan and at least 79 people were killed, authorities said on Wednesday.

The crash on the Herat-Kabul highway involved a motorcycle, a truck and a bus late on Tuesday, said Ahmdullah Muttaqi, head of the information department for Herat’s provincial government.

The bus was carrying Afghan refugees expelled from Iran, part of an exodus of hundreds of thousands of people, who were on their way from the border to Kabul.

Abdul Mateen Qaniee, the spokesperson for the Ministry of Interior, said that the bus caught fire after the accident, which happened a 30-minute drive outside Herat. He said on Wednesday that the death toll was 79, with 17 children among the deceased.

Video footage from the scene showed bright flames engulfing the bus, with a fire truck trying to douse the flames. A charred metal skeleton remained of the bus afterwards, pictures showed.

Traffic accidents are common in Afghanistan, with poor infrastructure exacerbated by decades of war, and drivers not following the rules.

“We urge transportation authorities to provide accurate information about the accident as soon as possible and to share their findings regarding the responsible party,” said Zabihullah Mujahid, spokesman for the Afghan government.

Herat, a key border province of Afghanistan touching Iran and Turkmenistan, is currently hosting tens of thousands of deported migrants from Iran.