Islamabad (CNN) -- Pakistan is condemning a suspected U.S. drone strike in one of its tribal regions that killed three people, raising questions about whether it will derail efforts between Islamabad and Washington to ease tensions over such attacks.
The suspected drone strike Sunday targeted a high school in the North Waziristan city of Miranshah where militants were hiding, intelligence officials said. North Waziristan is one of seven districts in Pakistan's tribal region that is believed to be a haven for militant groups.
"Such attacks are in total contravention of international law and established norms of interstate relations. The Government of Pakistan has consistently maintained that drone attacks are violations of its territorial integrity and sovereignty," according to a statement released Sunday by Pakistan's Ministry of Foreign Affairs.
"The matter will be taken up through diplomatic channels both in Islamabad and Washington."
The suspected drone strike in North Waziristan comes several weeks after Pakistani lawmakers approved a list of recommendations that includes a call for an immediate end to U.S. drone attacks.
There has been a sharp drop in the number of drone attacks in Pakistan since a November NATO airstrike that killed 24 Pakistani soldiers on the country's border with Afghanistan, driving U.S.- Pakistan relations to a low point.
Last week U.S. and Pakistani officials met in Pakistan to discuss relations between the two nations in the first in-depth talks since Pakistan's parliament rolled out a set of new guidelines for its relations with the United States, in which it agreed to re-engage with Washington after months of tension.
The list of parliamentary recommendations, approved by lawmakers and announced April 12, said that future relations with the United States should be based on mutual interest, and that no overt or covert operations -- including private security companies or operatives -- will be allowed on Pakistani soil.
U.S. officials rarely discuss the CIA's drone program in Pakistan, though privately they have said the covert strikes are legal and an effective tactic in the fight against extremists.
In January, President Barack Obama defended the use of drone attacks, saying a "pinpoint strike" is "less intrusive" on other countries' sovereignty than other military ways to target al Qaeda.
"Our ability to respect the sovereignty of other countries and to limit our incursions into somebody else's territory is enhanced by the fact that we are able to pinpoint-strike an al Qaeda operative in a place where the capacities of that military in that country may not be able to get them," Obama said.
CNN's Elise Labott contributed to this report.