A missile fired by a US drone has killed at least four people and injured five others in Pakistan's tribal region, officials say.

Pakistani officials confirmed the casualties of the Wednesday strike which the authorities allege had targeted a militant hide-out.

The attack was carried out in Shanakhora village in North Waziristan.

The US has come under increasing pressure to stop missile attacks in tribal areas near the Afghan border.

Earlier, a UN human rights investigator warned the US that its use of drones to kill alleged suspected Taliban militants may be in breach of international law.

In a report to the UN General Assembly, UN investigator Philip Alston said the targeted executions could be perceived as indiscriminate killing.

RZS/SS/RE