Two separate bus accidents hours apart in Pakistan on Sunday left at least 36 people dead and dozens more injured, officials said.

The first happened when a bus carrying Shiite Muslim pilgrims returning from Iraq through Iran fell from a highway into a ravine in south-west Pakistan, killing at least 12 people and injuring 32 others, police and officials said.

The driver lost control on the Makran coastal highway when the brakes failed while passing through Lasbela district in Baluchistan province, local police chief Qazi Sabir said.

Authorities in Baluchistan said arrangements are being made to send the bodies of pilgrims to Punjab province for burial.

Maryam Nawaz, the chief minister in Punjab, also expressed her condolences over the accident.

Hours later, 24 people, including two women and a child, were killed when a bus fell into a ravine in Kahuta district in eastern Punjab province, police and officials said. At least seven other people were injured.

The bus was heading to the Pakistan-administrated disputed Himalayan region of Kashmir – claimed in its entirety by both India and Pakistan – when it fell from the Panna bridge in the Kahuta district, said Sardar Waheed, a senior government official.

He added that heavy machinery is needed to lift the wreckage and ensure no-one is trapped underneath.

Pakistani President Asif Ali Zardari and Prime Minister Shehbaz Sharif in separate statements offered their condolences and expressed sorrow over the two accidents. They asked authorities to ensure the provision of the best medical treatment for the injured pilgrims.

The accidents on Sunday happened days after 28 Pakistani pilgrims were killed in a bus crash in neighbouring Iran while heading to Iraq.

A Pakistani military plane flew the bodies of the victims home on Saturday to be buried in southern Sindh province.

Thousands of Shiites travel to Iraq’s holy city of Karbala to commemorate Arbaeen – Arabic for the number 40 – to mark the death of the Prophet Muhammad’s grandson, Hussein, who became a symbol of resistance during the tumultuous first century of Islam’s history.

Bus accidents are common in Pakistan, mostly because of the negligence of the drivers who often violate traffic rules.