Pakistani officials have raised the death toll from a collision the previous day between a bus and an oil tanker to 27, saying DNA tests are required to identify most of the victims.

Pakistan volunteers arrange bodies of passengers killed in an accident, in Karachi, Pakistan, Tuesday, Jan. 22, 2019. A Pakistani official says a bus has collided with an oil tanker, killing many passengers and leaving another passengers with severe burns. [Photo: AP/Fareed Khan]

Local administrator Shabbir Mengal says that 14 people injured in the accident died overnight at hospitals.

Authorities had earlier said 13 passengers were killed and at least 16 others were injured in Monday's crash.

Mengal says the bus was going to Baluchistan from the port city of Karachi when the accident took place near the town of Hub. Shortly after the accident, flames engulfed the bus, which was carrying fuel smuggled from neighboring Iran in plastic containers.

Road accidents are common in Pakistan, where traffic laws are weakly enforced.