ISLAMABAD, Pakistan (CNN) -- An apparent drone attack on Monday killed four suspected militants in northern Pakistan, an intelligence source said.
An unspecified number of others were injured in the attack in the Khushhalee Turi Khel area of north Waziristan, according to the Pakistani source, who spoke on condition of anonymity because he is not authorized to speak to the media.
The remains were not in identifiable condition, area residents said.
The United States is the only country in the region known to have the ability to launch missiles from drones, which are controlled remotely. The U.S. normally does not comment on suspected drone strikes, which have caused tension between Pakistan and the United States in the past.
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The Pakistani military is fighting Taliban militants in the country's north, and missile attacks from suspected U.S. drones have targeted militant leaders.
CNN's Samson Desta in Islamabad contributed to this report.