Al Jazeera's correspondent in Pakistan, Kamal Hyder, said: "The attacks are the first since President Barack Obama took office and announced his special envoy for Afghanistan and Pakistan and, more importantly, on the eve of tribal chieftains meeting the president of Pakistan."
Tribal chiefs are expected to raise the issue of US drone attacks, which have killed civilians as well as armed fighters, and provoked considerable anger in the region.
Frustrated over what it sees as Pakistan's failure to stem the flow of al-Qaeda and Taliban fighters from its tribal regions into Afghanistan, the US stepped up cross-border attacks last year.
It carried out about 30 attacks using pilotless drones in 2008, according to a Reuters tally, more than half after the beginning of September.
The attacks have killed more than 220 people, according to Pakistani intelligence agents, district government officials and residents.
Pakistan objects to the attacks, saying they are a violation of its territory and undermine its efforts to tackle increasing fighter activity.
The strikes come one day after Obama, the new US president, appointed Richard Holbrooke as special envoy for Afghanistan and Pakistan.
|Tribesmen gather to pray a day before they raise the drones issue with the president [AFP]
Pakistan had hoped the new US administration would review its policy although during his election campaign had Obama spoken about the possibility of further missions in the area.
Asif Ali Zardari, the Pakistani president, and General Ashfaq Kayani, the chief of Pakistan's military, met David Petraeus, the US Central Command chief, in Islamabad on Tuesday to discuss ways that the US could assist the country in combating extremism.
US and Afghan officials have said Pakistan is not doing enough to combat fighters in the region, who have crossed over from Afghanistan to attack US and Nato troops.
Pakistan rejects those accusations.