CAIRO,(Reuters) – At least 29 people were killed and 16 others injured in a multi-vehicle road crash on a highway outside the Egyptian capital on Thursday, with fog the probable cause, security sources said.

The sources, speaking on customary condition of anonymity, said the accident happened when a bus and a minibus collided southeast of Cairo, causing a truck carrying bricks to overturn as the driver tried to avoid hitting them.

At least 10 other vehicles then rammed into the accident scene because fog had lowered visibility on the road and they could not see the crash. Many of the dead were killed after they left their vehicles to check for damage, the sources said.

State news agency MENA put the confirmed death toll from the crash at 25, but security sources and witnesses said rescue workers had extracted 29 bodies after sealing the road to prevent further crashes.

Reckless driving, lax traffic rules and poor road conditions contribute to many road crashes in Egypt. A series of fatal road and rail accidents in recent years has also triggered a public outcry over the government’s handling of transport safety.