An unmanned US aerial strike targeting a militant base in Pakistan's northwestern tribal area Monday morning killed at least 15 terrorists, Pakistani media reported citing security officials.

Two missiles hit the compound in Mir Ali, 25 kilometres east of Miranshah, the capital of North Waziristan, along the Afghan border, an area known to be a militant base and has been a target of several drone strikes since 2005.

This is the eighth drone strike in Pakistan since a NATO conference focusing on its operations in Afghanistan, held in Chicago last month.

Fifteen militants were killed in a dawn strike on a compound. The bodies of those killed were unable to be identified, an unnamed security official in Miranshah was quoted as saying by AFP.

There were reports that some foreigners had been killed in the attack, but the official couldn't confirm the news.

A drone attack Sunday killed at least five militants near Wana, in South Waziristan, according to Pakistani officials.

Despite Pakistan complaining that such drone attacks violate its sovereignty, US officials have largely opted to not discuss the CIA's drone program in Pakistan while privately saying that the covert attacks are legal and have proved to be an effective tactic against the militants.

The frequency of the drone strikes had risen after Obama took office in 2008, but has seen a sharp drop since a November NATO strike that killed 24 Pakistani soldiers on the Afghan border, causing fallout in the diplomatic relations between Washington and Islamabad.

Signaling a slight improvement in the diplomatic ties between Washington and Islamabad, the US military recently returned two officers to the headquarters of the Pakistani army's 11th Corps to help coordinate military actions along the Afghan border.

The officers were sent last month to Peshawar, close to the Afghan border, after months of severed ties following the controversial November attack. The US withdrew its military liaison officers and trainers following the fallout while Pakistan shut down all the NATO supply routes to Afghanistan in protest.

US Ambassador to Afghanistan Ryan Crocker had earlier said that the security pact signed May 2 by US President Barack Obama and Afghan President Hamid Karzai, which defines America's future role in Afghanistan, didn't rule out the possibility of drone strikes against insurgent targets in Pakistan even after the withdrawal of the US troops in 2014.