Islamabad: In the three powerful blasts that ripped through a crowded shrine in Pakistan's Punjab province, at least 42 people were killed and over a hundred were injured.

Hundreds of Sufi Muslims from different parts of the country had gathered at the shrine, called Sakhi Sarvar, near the Deraghazi Khan city for a three-day festival.

The first blast that was confirmed as a suicide attack occurred around 5.40 pm in the front side of the shrine, followed by a second blast at the rear end. The shrine is located on a mountain some 40 km from the city.

The third blast occurred near the shrine where people were busy helping the injured. It could not be determined immediately if the second and third blasts were suicide attacks. Scores of people were killed and injured in the blasts, sources told Xinhua. Geo TV said at least 42 people were killed and over a 100 injured.

Police had reportedly arrested two suspected terrorists near the shrine prior to the third blast. One of them was wearing a suicide jacket. Media reports said that the bomber in the first blast was aged between 17 and 22.

Rescue workers had difficulty in shifting the injured down from the mountain. It took about two to three hours to shift them to the nearest hospital, said a rescue officer. Many people have died on the way to the hospital, he said.

Prime Minister Yousuf Raza Gilani has strongly condemned the attack and ordered an immediate probe. Meanwhile, media reports said that Tehreek-e-Taliban Pakistan (TTP) has claimed responsibility for the attack.