DERA ISMAIL KHAN, PAKISTAN // A US drone fired two missiles at a compound in north-west Pakistan, killing four suspected militants in an attack that comes as Washington is running out of patience with Islamabad's refusal to reopen supply routes for Nato troops in Afghanistan.
Drone strikes have complicated negotiations over the routes, which Pakistan closed six months ago in retaliation for Nato air strikes that killed 24 Pakistani soldiers along the Afghan border.
The latest attack took place in Datta Khel Kalai village in the North Waziristan tribal area, said Pakistani intelligence officials.
While ties remain strained between the US and Islamabad, Pakistan appeared close to reopening the supply routes last week, prompting Nato to invite Asif Ali Zardari, the Pakistani president, to a major summit in Chicago this week.
But negotiations have faltered on Pakistan's demand for much higher transit fees.
The issue of drone strikes remains a sticking point between the US and Pakistan and is also complicated by the fact that some elements within the Pakistani government and military are widely believed to have supported the attacks in the past. That cooperation has declined as relations between the two countries have deteriorated.
The US refuses to discuss the covert CIA programme in detail in public, but officials have said in private that the strikes are a vital in the war against Al Qaeda and the Taliban.