At least four people were killed in a US drone attack in Pakistan's restive north-western tribal areas on Sunday, security officials said. The pilotless aircraft struck in Tabbi Tool area near Miran Shah, the major town in North Waziristan. The intelligence official said that two missiles were fired at a mud compound, dpa reported. "The reports that we have received from our informants, four people are killed and two more wounded," said an intelligence official who spoke on condition of anonymity. "The death toll may rise as locals believe more bodies are buried under the rubble," added the official. "Efforts are under way to pull them out." The identities of those killed were not known yet.