Four missiles slammed into the compound in the Baber Ghar area of South Waziristan, killing at least 18 people who were reported to be local Taliban fighters, the Pakistani security officials said in Peshawar, near the tribal belt that Washington considers an Al-Qaeda hub.

Another security official in Wana, the main town of South Waziristan, confirmed Wednesday's strike and casualties.

Officials said the attack took place at around 2:30 am (2130 GMT Tuesday) about three kilometres (two miles) from the border of Afghanistan's Paktia province, one of the flashpoints in the 10-year Taliban insurgency.

Wednesday's strike was the 63rd so far this year, according to an AFP tally.

On Tuesday, six militants were reported killed in a similar drone strike in Miranshah, the main town of the adjacent North Waziristan district.