Seven people were killed and four others injured in a U.S. drone strike early Wednesday morning in Pakistan’s North Waziristan region, security officials said.

It was the first attack since the May 11 general election in Pakistan and after U.S. President Barack Obama announced his new drone policy.

According to initial reports, two missiles were fired into a house in Chashma village in the town of Miranshah, which lies in the country’s tribal northwest and borders Afghanistan; it's known to be a stronghold for Taliban and al-Qaida-linked militants.

"Tribesmen started rescue work an hour after the attack and recovered seven bodies," said resident Bashir Dawar, according to Reuters.

A local security officer confirmed the attacks and added that the injured are in critical condition, Pakistan’s Dawn newspaper reported. It isn't yet clear if the victims were the targets.

Pakistan is a key ally of the U.S. in fighting militancy in the region, but heavy civilian casualties from drone attacks in the country have led to massive protests and fueled anti-American sentiment among the local population.

Pakistan’s government and its political parties have urged the U.S. to end its deadly drone strikes.

Nawaz Sharif, expected to take over as prime minister for a third term in early June, has expressed concerns over the ongoing use of U.S. drone strikes inside Pakistan’s territory.

Sharif, during his election campaign, had described the drone attacks as a “challenge” to the sovereignty of his country.

Imran Khan, the cricketer-turned-politician whose Pakistan Tehreek-e-Insaf party is expected to form a government in the northwestern Khyber Pakhtunkhwa province, has vowed to halt drone strikes.

On Thursday, Obama in a major speech on counter-terrorism policy defended the drone attacks as legal and said they saved lives. However, he also laid out new guidelines that are intended to limit or reduce their use.

Reacting to Obama’s statement that drones attacks are necessary, the Pakistani government on Friday reiterated its view that U.S. drone strikes in its territory is illegal.

“The Government of Pakistan has consistently maintained that the drone strikes are counter-productive, entail loss of innocent civilian lives, have human rights and humanitarian implications and violate the principles of national sovereignty, territorial integrity and international law,” the foreign ministry said in a statement, Dawn reported.

According to the London-based Bureau of Investigative Journalism, U.S. drone strikes in Pakistan have killed up to 3,587 people since 2004, of which 884 of them were civilians.