A bus collided with a truck on Kenya’s main highway on Sunday, killing at least 22 people, police said.

The crash came three weeks after 17 people died in another accident along the same highway linking the capital, Nairobi, with the coastal city of Mombasa.

Several others were injured in the Sunday morning crash and were receiving treatment, police said.

The passengers were reportedly returning from a funeral when the accident occurred.

Makueni County Commissioner Abdullahi Khalif said that the death toll could rise.

The circumstances surrounding the crash remain unclear. Speeding and poor road conditions have previously been cited as contributing factors in road accidents in Kenya.

Kenya’s National Transport and Safety Authority said the stretch of the highway where the crash occurred is a designated “accident black spot” and that recommendations had been made to address safety concerns.