ISLAMABAD, Dec. 8 (Xinhua) -- At least eight people were killed and 22 others injured in two separate road accidents in Pakistan's eastern Punjab province on Saturday, local reports said.

According to reports, at least five people were killed and five others critically wounded when a rickshaw rammed into an oil tanker coming from the opposite direction on Sargodha road in Sheikhupura, a city in Punjab province.

Police and rescue teams rushed to the site and shifted the deceased and injured people to the District Headquarters Hospital in the city.

The cause of the accident is not known yet, and police have launched an investigation into the matter, according to local media reports.

In another tragic accident, a passenger bus collided with an oil tanker, killing three people including two women on the spot while injuring 17 others near Chichawatni Bypass in Sahiwal city of Punjab province.

The ill-fated bus was travelling to the provincial capital city of Lahore from Multan, said police, adding that the accident occurred as the bus driver fell asleep while driving.

Commuters in Pakistan's Punjab are facing difficulties as fog engulfed many cities, dropping the visibility to zero especially at night time. Due to the fog, major roads were temporarily closed in several cities of the province, including the motorway.

Authorities have urged commuters to avoid unnecessary travel on the highways and motorways.