A bomb exploded near a Pakistani paramilitary checkpoint Sunday, killing at least 45 people near the country's eastern border with India in an attack suspected to be the work of a suicide bomber, police said.

The explosion hit near a checkpoint at the Wagah border crossing on the outskirts of Lahore, Punjab provincial police chief Mushtaq Sukhera said.

The death toll was likely to rise because over 70 people were wounded, with several in critical condition, he said.

Police are investigating the bombing, and had intelligence reports in advance that there could be such a blast in the city, he said.

Another Lahore officer, Haider Ashraf, said some paramilitary soldiers were among the dead and wounded. The paramilitary forces' provincial Director General Tahir Javed said three soldiers died.

All the officers said they did not know what the target could have been. No one has claimed responsibility for the bombing.

Security has been increased in all major Pakistani cities to thwart possible attacks on minority Shiite Muslims observing Ashura, a 10-day ritual to commemorate the death of Imam Hussain, the grandson of Prophet Muhammad.

But, Haider said, there was no such Shiite processions happening in the area where the incident took place.

Suspicion likely is to fall on Pakistani Taliban or any of their allied militant groups.

The militants have been waging a war against the state for over a decade in a bid to topple the government and install their own harsh brand of Islam, killing thousands of Pakistanis.