Bannu:
Three people were killed on Tuesday in a suicide bombing in Pakistan's restive North Waziristan tribal area, the first such attack there since the military launched a major operation against the Taliban and other militants.
The attacker detonated his car bomb in North Waziristan's Spinwam village when he was intercepted on the approach to a checkpoint, officials said, killing two soldiers and a civilian.
Pakistan's armed forces have used jet fighters, tanks and artillery in the offensive that began more than a week ago, killing around 300 people they have described as militants. The number and identity of the victims are impossible to verify.
"At least two soldiers and a civilian have embraced martyrdom," a security official told AFP.
The deaths bring to 12 the number of security forces killed in the offensive, dubbed "Zarb-e-Azb" after a sword used in battle by the Prophet Mohammad, since its launch on June 15.
A military statement said that troops stopped the suicide bomber 100 metres (yards) away from a checkpoint near a hospital and the action averted major casualties.
The Ansar-ul-Mujahedin militant group, a faction of the Pakistani Taliban, claimed responsibility, with spokesman Abu Baseer saying it was the start of a counter-offensive against Pakistani troops.
"It is beginning of our offensive and we will launch attacks against government and local tribesmen if they form an anti-Taliban force," Baseer told AFP via telephone from an unknown location.
Meanwhile, Pakistani jets and helicopter gunships targeted militant hideouts at several locations in North Waziristan, officials said.
The offensive has seen the tribal district hit by more than a week of shelling and air raids. More than 470,000 people have fled ahead of an impending ground assault, with many going to the nearby town of Bannu.
Police and troops were forced to fire warning shots on Tuesday to quell a protest about problems with food distribution in Bannu.
An AFP reporter saw around 500 people blocking a main road into the town and pelting security forces with rocks in protest at delays in receiving aid, prompting police and soldiers to fire in the air to disperse them.
The UN said Tuesday that up to half a million people could be displaced by the current military operation and urged the Pakistani government to allow its agencies access to the affected areas.
The assault on the militant bastion of North Waziristan, long urged by Washington, came after a bloody and dramatic attack on Karachi airport brought an end to months of largely fruitless government efforts to negotiate a peace deal with the Tehreek-e-Taliban Pakistan.