| PESHAWAR, Pakistan
PESHAWAR, Pakistan Suspected U.S. drone aircraft strikes killed 15 Muslim militants in northwest Pakistan on Saturday, suggesting there will no letup this year in a campaign Washington says is hurting al Qaeda-linked groups.
The attacks by unmanned U.S. drone aircraft were reported by local Pakistani intelligence officials in North Waziristan -- a sanctuary for al Qaeda and Taliban militants on the Afghan border. A day earlier, five militants were killed by drones in the same region.
The intensity of the attacks could mean a high-value target was spotted in the ethnic Pashtun tribal region.
Leaders of the Haqqani network, one of the most lethal Afghan militant factions fighting U.S.-led NATO troops in Afghanistan, are based in North Waziristan.
Pakistan has resisted U.S. pressure to launch a full-scale offensive in North Waziristan, saying it is consolidating gains from major operations against militants in other tribal areas.
Critics say Pakistan's reluctance stems from its desire to keep the Haqqani network as an asset in any future political settlement in Afghanistan.
It is one of the most sensitive issues in often uneasy relations between the United States and Pakistan.
Seven insurgents were killed in the first drone strike on Saturday when four missiles hit a vehicle and a militant compound in Mir Ali town in North Waziristan.
Most of the militants were believed to be loyal to Hafiz Gul Bahadur, a commander affiliated with the Haqqani network, said a local intelligence official.
Shortly afterwards, two more missiles were fired at the same site, killing four militants busy in rescue work.
Then, a suspected drone missile attack killed four militants when it struck their vehicle about 30 km (18 miles) from North Waziristan's main town, Miranshah.
There was no independent confirmation of the incidents and militants often dismiss official casualty figures.
The strikes, which have intensified under the Obama administration, have killed high-profile militants.
Pakistan worries the attacks undermine efforts to deal with militancy because civilian casualties inflame public anger and bolster support for the militants. Analysts say major successes would not be possible without Pakistani intelligence, however.
Drones allow the United States to kill militants from a distance. Using human informants is risky; militants often behead suspected spies for the United States.
Long-term stability in Pakistan's northwest, however, depends mostly on economic development because poverty and unemployment can drive young Pakistani men to join militant groups who persuade them holy war is glorious.
The Pakistani government, which has relied on an $11 billion IMF loan agreed in 2008 to keep the economy afloat, does not have the resources to invest in the northwest tribal areas, where it has virtually no control.
(Writing by Zeeshan Haider; editing by Michael Georgy and Philippa Fletcher)