At least 33 people have been reported dead while 40 others were injured after a bus rammed into a container on Monday.

Senior police officer Hassan Javed said the bus was heading to the city of Dera Ghazi Khan in eastern Punjab province. The exact cause of the accident is still under investigation.

The packed bus was filled with passengers heading home for the Muslim Eid al-Adha holiday when the accident happened.

The holiday is one of the biggest celebrations on the Muslim calendar where families slaughter animals and share the meat with the poor.

What we know so far

Sher Khan who is in charge of the rescue team at the site said some of the injured were in critical condition. The bus driver was among those killed on sight.

Footage on television and photos circulating on social media showed rescuers trying to pull out bodies from the mangled bus.

Pakistan's Information Minister Fawad Chaudhry expressed his condolences on Twitter and advised public transport drivers to be more careful of the lives of the people they have been entrusted with.

"When will we as a nation realize that violation of traffic rules is fatal? Public transport drivers are the trustees of people's lives,” he tweeted.

Deadly road accidents in Pakistan are quite common because of poor road infrastructure and disregard for traffic laws.

on/rc (AP, AFP)