Pakistan is still counting the cost of this week's Peshawar car bomb

At least seven paramilitary troops have been killed by a roadside bomb in north-west Pakistan, say officials.

Eleven others were said to have been injured in the blast, which struck a routine patrol of troops in the Khyber tribal region.

Elsewhere, officials said more than a dozen Islamist militants died in air strikes in the Orakzai tribal region.

The latest attacks came as fierce fighting continued in South Waziristan between the army and insurgents.

Saturday's bomb hit a vehicle carrying troops in Sur Khar, to the east of Khyber's main town, Landikotal, a Frontier Corps spokesman told Reuters news agency.

We are at war

Yousuf Raza Gilani

Prime Minister

Pakistan's hidden war

Meanwhile, at least 13 insurgents died as warplanes raided suspected militant hideouts in Orakzai, said government officials.

Pakistan's prime minister told a news conference on Saturday that the country's leadership was united in its efforts to wipe out the Taliban.

"We are at war," Yousuf Raza Gilani said, quoted by AP news agency. "We do not have any other option because their [the militants'] intentions are to take over," he added.

Two weeks ago, the army launched its offensive in South Waziristan, the tribal territory separating Pakistan and Afghanistan that is widely regarded as a haven for the Taliban and al-Qaeda.

The militants have carried out retaliatory attacks across the country.

They were blamed for Wednesday's car bomb in Peshawar that killed at least 115 people, including many women and children, but the Taliban have denied responsibility.

That blast struck during a three-day visit by US Secretary of State Hillary Clinton.

During the trip, she said it was "hard to believe" no-one in Pakistan's government knew where al-Qaida's leadership was hiding.