At least 42 people were killed and over one hundred others injured in three serial blasts that occurred Sunday afternoon at a crowded shrine in Pakistan`s central city of Deraghazi Khan, reported local Urdu TV channel Geo by quoting rescue officials, according to Xinhua.

According to the local media reports, hundreds of people coming from different parts of the country were gathering inside the shrine to pay their tribute to the great saint when the blasts took place.

The first blast, which has been confirmed to be of suicide nature, took place at about 17:40 pm local time at the front part of the shrine, which is located at the top of a mountain some 40 kilometers away from the afore-said city, followed by a second blast at the back part of the shrine.

In the first two blasts, a dozen people were reportedly killed and over 60 others injured, said sources in the city in a telephone interview with Xinhua.

The third blast, which did not come until about an hour later, took place somewhere near the shrine where people were busy with helping the injured people on the blast site.

The nature of the second and third blasts has not been determined. Some local media reported that the third blast is also of suicide nature.

Prior to the third blast, police reportedly arrested two suspected terrorists on the spot including one wearing suicide jacket. The suicide bomber arrested by the police is said to be from the northwestern part of the country.

Local media reports quoted police sources as saying that the suicide bomber in the first blast, who killed himself right on the spot, is aged between 17 to 22.

As the shrine, which is called Sakhi Sarvar, is located atop a mountain, rescue workers had to fight the difficulty terrains in shifting the injured people down from the mountain.

It took about two or three hours to get the injured people down from the mountain to the nearest hospital which is located some 40 kilometers away, said a rescue officer, adding that many critically injured people died before they reached the hospital.

Shortly after the blasts were reported, the Pakistani Prime Minister Gilani issued a statement strongly condemning the terrorist attack at innocent civilians and ordered an immediate investigation into the case.

Latest news coming in said that TTP (Pakistan Taliban) has claimed the responsibility for the serial blast attacks at the Sakhi Sarvar shrine.

Sunday`s terrorist attack at a shrine is the first of its kind reported in the country since this year. Last year several suicide blast attacks at shrines were reported in different parts of the country. One attack at a shrine in Pakistan`s eastern city of Lahore on July 1 is the most serious, leaving 37 people dead and over 170 others injured. The Lahore shrine attack was later followed by one in Karachi and another in Pak Pattan, a city in eastern part of Pakistan.

As the militants in Pakistan are facing the ever-mounting pressure from the strikes launched by the Pakistani security forces in the country`s northwestern tribal areas bordering Afghanistan, they have changed their strategy by avoiding direct conflict with the armed forces and shifting to attack at the so- called "soft targets" such as civilians, government office buildings and infrastructure in a bid to force the government to stop the strikes against them.