Islamabad, Pakistan (CNN) -- The Pakistani Taliban claimed responsibility for Saturday's blast in that Asian nation's tribal region, an explosion at a food distribution point that killed at least 43 people and injured 90 others.

Azam Tariq, the central spokesperson for Pakistani Taliban, told CNN in a phone call that it targeted people who had formed what he called a pro-government and anti-Taliban group.

The blast took place about 600 meters from a U.N. World Food Programme distribution point at a security check post in Khar, according to Amjad Jamal, a spokesman for the agency. He said that more than 300 people were going through a security screening to get food and other items at the time of the explosion.

Khar is the headquarters of Bajaur Agency, one of the seven districts of Pakistan's tribal region bordering Afghanistan. Jamal said that those who had been internally displaced during military efforts in Bajaur Agency get a month's supply of food and other goods.

Dr. Muhammad Hanif, a senior medical officer of Bajaur Agency's headquarters hospital in Khar, told CNN that 43 dead bodies and 90 injured people had been brought to the hospital.

Jamal said all staff members of the World Food Programme and its partner organizations are safe, but added that all four of the program's food distribution points in Bajaur Agency have been temporarily closed for security reasons. Still, the U.N. agency will continue to provide services elsewhere in the country, Jamal said.

Responding the question that whether the suicide bomber was a woman, the Pakistani Taliban's Azam Tariq said, "We have thousands of male suicide bombers ready who are keenly waiting for their turns. Then why would we use a woman, which is against the traditions of Islam?"

U.S. President Barack Obama issued a statement condemning Saturday's "outrageous terrorist attack," which he called "an affront to the people of Pakistan and to all humanity."

"The United States stands with the people of Pakistan in this difficult time, and will strongly support Pakistan's efforts to ensure greater peace, security and justice for its people," Obama said.

The blast took place a day after about 150 militants fired at five security checkpoints in Mohmand Agency -- another of the seven districts in Pakistan's volatile tribal region along the Afghan border -- killing 11 soldiers. Security forces later killed 40 militants who were among the group, authorities said Saturday.

The security forces pounded militant hideouts in Mohmand Agency with helicopter gunships, said Maqsood Amin, a senior government official in the area. Twenty-four militants were killed during retaliation Friday while 16 were targeted Saturday.

CNN's Chris Lawrence contributed to this report.