An ambulance arrives at the site of a bomb attack at the Jalozai refugee camp in northwest Pakistan's Nowshera on March 21, 2013. At least 12 people were killed and 35 others injured when a bomb hit a refugee camp in Nowshera on Thursday morning, local officials said. (Xinhua Photo/Umar Qayyum)

Security officials examine a damaged vehicle at the site of a bomb attack at the Jalozai refugee camp in northwest Pakistan's Nowshera on March 21, 2013. At least 12 people were killed and 35 others injured when a bomb hit a refugee camp in Nowshera on Thursday morning, local officials said. (Xinhua Photo/Umar Qayyum)

Security officials examine damaged vehicles at the site of a bomb attack at the Jalozai refugee camp in northwest Pakistan's Nowshera on March 21, 2013. At least 12 people were killed and 35 others injured when a bomb hit a refugee camp in Nowshera on Thursday morning, local officials said. (Xinhua Photo/Umar Qayyum)

Security officials examine damaged vehicles at the site of a bomb attack at the Jalozai refugee camp in northwest Pakistan's Nowshera on March 21, 2013. At least 12 people were killed and 35 others injured when a bomb hit a refugee camp in Nowshera on Thursday morning, local officials said. (Xinhua Photo/Umar Qayyum)

Local residents gather at the site of a bomb attack at the Jalozai refugee camp in northwest Pakistan's Nowshera on March 21, 2013. At least 12 people were killed and 35 others injured when a bomb hit a refugee camp in Nowshera on Thursday morning, local officials said. (Xinhua Photo/Umar Qayyum)

Local residents gather at the site of a bomb attack at the Jalozai refugee camp in northwest Pakistan's Nowshera on March 21, 2013. At least 12 people were killed and 35 others injured when a bomb hit a refugee camp in Nowshera on Thursday morning, local officials said. (Xinhua Photo/Umar Qayyum)

Security officials examine the site of a bomb attack at the Jalozai refugee camp in northwest Pakistan's Nowshera on March 21, 2013. At least 12 people were killed and 35 others injured when a bomb hit a refugee camp in Nowshera on Thursday morning, local officials said. (Xinhua Photo/Umar Qayyum)

A security official stands guard at the site of a bomb attack at the Jalozai refugee camp in northwest Pakistan's Nowshera on March 21, 2013. At least 12 people were killed and 35 others injured when a bomb hit a refugee camp in Nowshera on Thursday morning, local officials said. (Xinhua Photo/Umar Qayyum)

A man mourns over the death of his relative at a hospital in northwest Pakistan's Peshawar on March 21, 2013. At least 12 people were killed and 35 others injured when a bomb hit a refugee camp in Pakistan's northwest city of Nowshera on Thursday morning, local district officials said. (Xinhua/Ahmad Sidique)

Rescuers transfer an injured man to a hospital in northwest Pakistan's Peshawar on March 21, 2013. At least 12 people were killed and 35 others injured when a bomb hit a refugee camp in Pakistan's northwest city of Nowshera on Thursday morning, local district officials said. (Xinhua/Ahmad Sidique)

Rescuers transfer an injured man to a hospital in northwest Pakistan's Peshawar on March 21, 2013. At least 12 people were killed and 35 others injured when a bomb hit a refugee camp in Pakistan's northwest city of Nowshera on Thursday morning, local district officials said. (Xinhua/Ahmad Sidique)

Rescuers transfer an injured man to a hospital in northwest Pakistan's Peshawar on March 21, 2013. At least 12 people were killed and 35 others injured when a bomb hit a refugee camp in Pakistan's northwest city of Nowshera on Thursday morning, local district officials said. (Xinhua/Ahmad Sidique)