explosion debris
© AFP 2016/Ali Jan
Police in Pakistan say a large bomb has exploded at a protest rally in the city of Lahore, with early reports suggesting at least two people had died.

The blast struck outside the Punjab Assembly, injuring several people, including police officers and journalists covering the march.

Vehicles on Lahore's Mall Road, a major thoroughfare that passers through the centre of the city, were also destroyed.

No group has yet claimed responsibility for the blast, which appeared to come from a parked car.

Rescuers are at the scene and the area has been cordoned off.

The protest was organised by the owners of pharmacies in Punjab who are unhappy about new drug rules enforced by the regional government.

An unconfirmed report said Lahore police had named a senior traffic officer as the first casualty.

A second chief of police was separately named as having been killed in the blast.

Lahore is the capital of Punjab province and was targeted on Easter Sunday last year in an attack that claimed the lives of 75 people.

That suicide bombing targeted Christians although the majority of the dead were Muslim.

A group affiliated with the Pakistani Taliban claimed responsibility for the attack.

Thousands of suspected terrorists were arrested as part of Pakistan's paramilitary crackdown on Islamist militants in the wake of the attack.