Peshawar, Pakistan (CNN) -- Eleven people were killed Saturday when two vans carrying a polio vaccination team were hit by a roadside bomb in Pakistan's northern Khyber Agency, authorities said.
Among the dead was an 8-year-old child; 12 other people were wounded, Khbyer Agency surgeon Dr. Rehman Khan said. Ten of the fatalities were tribal policemen called Khasadars, he said.
Though the security forces and militants engaged the attackers in a gun battle, the militants escaped, he said.
The child was caught in cross-fire, said Dr. Sameen Jan Shinwari, medical superintendent of Agency Headquarters Hospital in Jamrud.
The Khyber Agency is a loosely governed tribal region that borders on Afghanistan.
Pakistan's military had resumed operations against suspected Taliban strongholds in Khyber and other nearby agencies, after peace talks with the militant group broke down last month in the wake of attacks by the group.
Earlier this week, government airstrikes demolished suspected Pakistani Taliban hideouts in Waziristan and may have killed dozens, the military said.
But, after Saturday's attack in Khyber Agency, the Pakistani Taliban announced a month-long cease-fire, the group's spokesman, Shahidullah Shahid, told CNN.
A government spokesman said the committee charged with holding talks with the TTP welcomed the announcement as a "positive development," but had received no official cease-fire offer.
The government's committee is expected to meet early next week to discuss the development.
A militant group, which has connections to the Pakistani Taliban, opposes polio vaccinations, accusing polio workers of pursuing a political agenda.
Anti-polio campaigns have been targeted by militants in Pakistan since U.S. intelligence officials used a fake vaccination program to help in their hunt for Osama bin Laden in 2011. Under cover of the program, the CIA sought to collect DNA samples from relatives of the al Qaeda leader to verify his presence in a compound in Abbottabad.
Since July 2012, at least 22 polio workers have been killed.
The polio campaign has a history of controversy in Pakistan. Some mullahs have preached against it, claiming falsely that the oral vaccine leaves Pakistani children sterile.
Last year, a Taliban commander in northwest Pakistan announced a ban on polio vaccines for children in the region as long as the United States continued its campaign of drone strikes.
Polio, which can cause permanent paralysis in hours, remains endemic only in Pakistan, Nigeria and Afghanistan.
CNN's Saleem Mehsud in Islamabad and Ben Brumfield contributed to this report