At least 12 people have been killed and 30 injured in a bomb explosion in Pakistan's troubled tribal area bordering Afghanistan, officials say.
The blast ripped through a hotel and shops in a market in Jandola town in South Waziristan.
Earlier this week four soldiers were kidnapped in South Waziristan and 15 people killed in clashes in neighbouring North Waziristan.
It is the worst violence in the region for several weeks.
The central government began deploying soldiers in large numbers in the tribal areas two years ago to counter the movements of members of the Taleban, al-Qaeda and their supporters.
The BBC's Aamer Ahmed Khan in Karachi says the army is in control of the main population centres and road routes.
However, he says the military cannot reduce its heavy presence because it has not been able to gain the trust of many of the tribesmen there.
There were two explosions in Jandola town on Thursday.
The first one was the hotel bomb that left 12 dead, officials say. The hotel is situated on land owned by the army.
The security forces have suffered heavy casualties in Waziristan
It is not clear who planted the device.
The hotel is next to the headquarters of the local paramilitary force.
Ninety minutes later there was a second explosion in the same market area of the town. Officials say this blast was caused by fire in an arms and ammunition shop, local officials say.
Four paramilitary soldiers and a journalist have gone missing in South Waziristan in recent days.
The bodies of two of the soldiers have now been found. One report said they had been beheaded, another that their throats had been cut.
South and North Waziristan have been at the centre of prolonged confrontations between the army and militant groups.
Hundreds of militants and more than 250 Pakistani soldiers have died in the tribal areas along the border with Afghanistan in the past two years.
'Hung from poles'
North Waziristan saw a further development this week when 15 people were killed in clashes that started after bandits tried extorting money from Islamic students at a roadblock.
The students, backed by local tribesmen sympathetic to the Taleban, set fire to the gangsters' homes.
They then hung the bodies of at least three of the bandits from electricity poles. Residents said the fighting was so fierce the authorities did not intervene.
Pakistan has sent thousands of soldiers to hunt down the militants as part of the US-led war on terror.
Last week the Pakistanis authorities said a leading al-Qaeda member, Abu Hamza Rabia, was killed in an explosion in North Waziristan.