Two bomb attacks killed at least 23 people Monday in tribally administered regions in Pakistan close to the Afghan border, officials and a witness said.

The deadliest blast was a suicide attack at a mosque inside a religious school in South Waziristan, according to an intelligence official in the region. He spoke on condition of anonymity in line with the orders set down by his agency.

He said Maulana Noor Mohammad, a former lawmaker who ran the school, was among the 16 dead.

Yar Mohammad, a local tribesman who was inside the mosque, also said it was a suicide blast.

There was no claim of responsibility, though Islamist militants have often attacked clerics or others who do not support them. It was unclear whether Mohammad fell into that category. Militant and tribal factions also fight among themselves.

Earlier, a bomb exploded inside a school during a meeting of elders in Kurram, killing seven people.

Local official Khalid Umerzai said the elders at the meeting were discussing a disagreement over ownership of the school building. It wasn't clear if the blast was tied to that dispute or if it had been launched by Islamist militants.

The Pakistani army has launched offensives in South Waziristan and Kurram over the last 18 months.

There is little or no government presence in either area.

Later Monday, missiles fired from a U.S. pilotless drone aircraft killed 13 militants and 7 civilians in North Waziristan, Pakistani intelligence officials said.

They said the missiles were fired at a militant hideout, killing members of the Afghan Taliban. Among the dead were four women and three children, said the officials.