The Taliban spokesman said the bomber was a man.
Elsewhere, at least a dozen people, some of them foreign fighters, have been killed in a suspected US air raid in northwestern Pakistan, according to a security official.
"We have reports that the missile strike killed at least 12 militants including some foreigners," he said.
He said the two houses belonged to Maulvi Taj Mohammad and Maulvi Hassan, two men who he said were "al-Qaeda facilitators".
Separately, the Pakistani army said it was unaware of any missile strike in the region.
"We have no information about the strike," Major-General Athar Abbas, a military spokesman, said.
He also said that the army was not in the area.
Although there were no immediate claims of responsibility for the attack, a US drone targeted Ayman al-Zawahiri, al-Qaeda's deputy leader, in Damadola in January 2006, killing several people but missing him.
A similar missile strike on a pro-Taliban camp in another tribal area killed 10 people in November last year, though it was not clear who was responsible.
Pakistan's army at the time said it was not involved while the US-led coalition in Afghanistan, the only force known to operate drones in the area, said it was not aware of any activity.
The attack on Wednesday came as a Nato spokesman said Pakistan was not doing enough to improve security on its border with Afghanistan following a rise in cross-border attacks by Taliban fighters and al-Qaeda supporters.
"The number of attacks is up significantly from the same period last year," James Appathurai, the group's chief spokesman , said in Brussels.
"There is not enough effectiveness in border control on Pakistan's side."
Pakistan's new government has launched peace talks with fighters in the area and this week moved troops away from villages and towns in the tribal region bordering Afghanistan.
As part of the process, more than 30 tribesmen held in various prisons were freed on Tuesday in return for the release of a dozen soldiers detained by pro-Taliban fighters, a security official said.