Islamabad, Pakistan (CNN) -- At least 22 people were killed and 38 others injured in a blast at an army checkpoint in the northern Pakistani city of Bannu on Sunday, intelligence officials said.
The blast struck an army convoy traveling from Bannu to Miranshah, the officials said. The convoy included both military and civilian vehicles.
According to the intelligence officials, an improvised explosive device had been planted in an 18-seater van. The majority of those killed were passengers on that van.
In the wake of the attack, which he strongly condemned, Pakistani Prime Minister Nawaz Sharif said he was canceling a planned trip to Davos, Switzerland. The World Economic Forum starts there Wednesday.
"Our nation is united against extremism and terrorism and the sacrifices rendered by our citizens and personnel of law enforcing agencies will not go in vain," Sharif said, in a statement from his office.
Pakistani Interior Minister Chaudhry Nisar Ali Khan also condemned Sunday's attack and has sought an explanation about the hiring of the private vehicles used in the convoy.
The main Pakistani Taliban faction, known as Tehrik-e-Taliban Pakistan, claimed responsibility for the blast.
"The bombing was carried out to (avenge) the killing of Maulana Waliur Rehman, commander of TTP South Waziristan, who was killed on May 29, 2013, in a U.S. drone strike in Miranshah," TTP spokesman Shahidullah Shahid said.
It's not the first attack carried out by the TTP to avenge Waliur Rehman's death. Gunmen opened fire at the base of one of Pakistan's highest peaks in June 2013, killing 11 people -- 10 tourists and a local guide.
Taliban 'conducive to talks'
Despite the violence, the TTP on Sunday called for fresh talks with the Pakistani government, in a news conference recorded by its media wing.
Senior leader Azam Tariq, appearing alongside spokesman Shahidullah Shahid, claimed that the TTP has "always been conducive to talks but that the media has been twisting the TTP's stance in a negative light."
The pair said that continuing talks was "not in the hands of the TTP but in that of the Pakistani government."
"It is the Pakistani government on the order of the United States that started the war on the homes of the TTP and it is only the Pakistani government that can stop this war," said Tariq. "It is in the hands of the government to create an environment where talks can take place."
Tariq also said that the authorities were "using the media as a medium of propaganda for their war."
The Taliban have stepped up attacks on news outlets in Pakistan. On Friday, a targeted attack on a local channel's digital satellite newsgathering vehicle left three employees dead.
Journalists Zahir Shah Sherazi and Saleem Mehsud contributed to this report.