DERA ISMAIL KHAN, PAKISTAN - A second US missile strike in as many days slammed into a Taliban compound Wednesday in the lawless tribal stronghold of Pakistan militant chief Baitullah Mehsud, officials said.

Missiles fired from an unmanned drone aircraft hammered a training centre for Islamist extremists in South Waziristan about 35 kilometres (21 miles) northeast of the main town Wana, and near the site of Tuesday's strike.

"There was a US missile strike on a Taliban compound in Karwan Manza area of South Waziristan," said a security official in Pakistan's northwest, adding that the strike hit in the early hours of Wednesday.

Another security official said local sources were reporting between eight and 10 people killed, but said that the death toll was yet to be verified in an area largely outside of government control.

Other local residents, meanwhile, told officials the targeted building was empty at the time of the attack.

On Tuesday, a US missile strike pulverised a compound killing 16 foreign and local militants in a nearby mountain stronghold of Mehsud, who has a five-million-dollar bounty on his head offered by the United States.

Suspected US attacks and Pakistani air strikes have increasingly targeted hideouts used by Mehsud, described by the US State Department as a key Al-Qaeda facilitator in Pakistan's mountainous tribal region along the Afghan border.

Pakistani troops have been pressing a two-month battle to dislodge Taliban insurgents in three northwest districts and have carried out air raids in South Waziristan ahead of a widely expected ground assault against Mehsud.

The United States military does not, as a rule, confirm drone attacks, but its armed forces and the CIA operating in Afghanistan are the only forces that deploy unmanned aircraft in the region.

Pakistan publicly opposes US strikes, saying they violate its territorial sovereignty and deepen resentment among the populace.

Since August 2008, at least 45 such strikes have killed around 450 people.