At least 30 people were killed and dozens of others injured in two back to back explosions near an Internally Displaced Persons's (IDP) camp in northwest Pakistan 's Kohat on Saturday, police sources said.

Local officials told Xinhua that one blast occurred at the registration point while the second occurred when people gathered on the spot.

According to local sources, both blasts were suicide attacks.

The blasts took place one after another in 10 minutes at a relief distribution camp near the city of Kohat for people displaced as the result of a military operation in Orakzai tribal agency, police said.

When the people rushed to the camp site for relief activities, the second blast happened, according to witnesses. Police said that the second blast caused serious damage.

Gunshots were heard soon after the blast in the IDP's camp, witnesses said. Several buildings were damaged in the blasts.

The security forces and law enforcement agencies put security cordon around the blast site.

The camp called "Kacha Pakha" is located some 20 kilometers from Kohat, main city in the region. Officials said that some 300 IDPs were living in the camp.

Some 200,000 people have been displaced as the result of the military offensive against the Taliban militants in Orakzai agency.

The IDPs have been camped in Kohat and Hangu districts.

The injured were shifted to hospitals in Kohat and Hangu and the authorities declared emergency in hospitals.

Geo television said that some 50 people were injured, several of them are in critical condition.

No group has claimed responsibility for the attacks but suspected Taliban are blamed for such attacks.