The officials said the incident took place in Turbat district near the Iranian border.  Baluchistan is home to various militant groups, including pro-Taliban factions, as well as Baluch militants.  The province has been in the grip of a regional insurgency for years as separatist militants fight for more autonomy and greater control over natural resources.

The ambush came less than 24 hours after a U.S. drone strike killed four suspected militants in the country's northwest.

Pakistani officials said the missiles hit a compound near Miran Shah, the main town in the North Waziristan tribal region, late Tuesday.  U.S. officials confirmed the attack.

The strike was the first since NATO helicopters operating out of Afghanistan mistakenly killed 24 Pakistani soldiers along the border last November.

That attack worsened already strained U.S.-Pakistan relations and prompted Pakistan to block supply routes for NATO troops in Afghanistan. 

American officials have denied that the recent drop-off in drone strikes was deliberate.

But in December, a prominent U.S. newspaper said the Central Intelligence Agency had suspended drone strikes targeting low-ranking militants in Pakistan for six weeks in an effort to mend badly frayed relations with the South Asian nation. 

The Los Angeles Times quoted unnamed U.S. officials as saying the CIA's "undeclared halt" in attacks was aimed at reversing a "sharp erosion of trust" between the two countries, following a series of deadly incidents, including the NATO attack in November. 

Drone strikes in Pakistan are credited with killing dozens of al-Qaida operatives and hundreds of low-ranking fighters since 2004.  But, at the same time, they have infuriated many Pakistanis and complicated relations between Washington and Islamabad.

Some information for this report provided by AP and AFP.
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