At least five killed in blast in northern Afghanistan, say police

At least five people were killed when a blast hit a vehicle carrying employees of an oil company in northern Afghanistan, police said on Tuesday.

"Today around 7 am a blast took place in Balkh on a bus, which belonged to Hairatan Oil employees," said Mohammad Asif Wazeri, police spokesman for northern Balkh province, adding that at least four people were also injured in the explosion.

It was not immediately clear who was behind the blast.

Several attacks have taken place in urban centres in recent months in Afghanistan, some of which have been claimed by Islamic State.