PESHAWAR A suspected US drone aircraft fired two missiles into a house in Mir Ali in Pakistan's North Waziristan region on the Afghan border on Thursday, killing four people and wounding five others, Reuters quoted two Pakistani intelligence officials as saying.

It was the second strike in as many days. A missile believed to have been launched by a US drone killed at least seven militants, including foreigners, in South Waziristan on Wednesday, intelligence officials and Taliban sources said.

However, senior Pakistani officials on Thursday denied there had been a suspected US missile strike in the region.

There was no missile strike, said Habibullah Khan, a top official in the administration of the Federally Administered Tribal Areas.

Two senior security officials, who declined to be named, also denied there had been a missile strike but declined to speak on the record.

Residents in the area said they had heard an explosion in a house, but witnesses had no details about any possible casualties or bodies.