Twenty-one people were killed and 38 injured on Sunday in southern Afghanistan's Helmand province when a bus collided with an oil tanker and a motorbike, provincial officials said.

Deadly traffic accidents are common in the country, due in part to poor roads, dangerous driving on highways and a lack of regulation.

"On Sunday morning, 21 people were killed and 38 people were injured due to a collision between a tanker, a motorcycle and a passenger bus," the provincial information department said in a post on X.

The accident took place on the Herat-Kandahar highway in Grishk district of Helmand province, it added.

The collision caused the vehicles to ignite, Helmand governor spokesman Mohammad Qasim Riyaz told AFP.

Images shared by the information department on social media showed charred, twisted metal scattered across the highway and the crushed cabin of the tanker.

Clean up crews were on site removing the debris, according to officials.

Of the injured, 11 were seriously hurt and 27 had minor injuries.

The passenger bus was travelling from Herat city to the capital Kabul when it first collided with a motorbike carrying two people, killing both riders, Helmand traffic management officials said, according to the information department.

The bus driver lost control and crashed with an oil tanker travelling in the opposite direction from the southern city of Kandahar to Herat, sparking a fire.

The accident killed three people on the tanker and 16 bus passengers.

Another serious accident involving an oil tanker took place in December 2022, when the vehicle overturned and caught fire in Afghanistan's high-altitude Salang pass, killing 31 people and leaving dozens more with burn injuries.