PESHAWAR, Pakistan (Reuters) - The militant Pakistani Taliban group said it carried out an attack on Sunday that killed five people in the tribal areas bordering Afghanistan.

Tehreek-e-Taliban Pakistan (TTP) spokesman Mohammad Khurassani said the militants planted an improvised explosive device “to target security personnel” in the Bajaur Agency area that is part of the Federally Administered Tribal Areas (FATA).

The blast struck a vehicle in the Mamund area of Bajaur, killing four security personnel and an official from the civilian administration, local government sources said.

Bajaur is one of the Pashtun tribal regions near the Afghan border. Security in the region has improved in recent years after the Pakistani military mounted offensives there against the al Qaeda-linked Pakistani Taliban, which is considered the country’s biggest security threat.

But militants continue to stage attacks in FATA, which remains off-bounds for foreigners and is considered one of the most volatile parts of the nuclear-armed nation of 208 million people.