Pakistani officials say at least 20 people were killed and 20 more injured Sunday when a passenger bus veered off the road and fell into a ravine in the country's southwest.

The officials said the bus was carrying pilgrims from the Shah Noorani shrine in Baluchistan province to Sindh province when the driver lost control of the bus on a mountainous road, causing it to plunge into a deep gorge.

Deadly road accidents are common in Pakistan. Officials blame most accidents on reckless driving, old vehicles and poorly maintained roads.