ISLAMABAD, Pakistan (CNN) -- The suspected mastermind of the suicide strike on the offices of the U.N. World Food Programme in Islamabad has been arrested, Pakistan's interior minister said on Friday.
The attack -- which killed five employees and wounded several others on Monday -- was planned in South Waziristan, part of Pakistan's lawless tribal region where militants have maintained a strong presence, Rehman Malik told reporters.
Malik said the suspect is being questioned and more details will be made available to the media within the next 24 hours.
Four Pakistanis and an Iraqi national died at the U.N. humanitarian agency, according to authorities. The suicide bomber, who also died in the attack, was in his 20s and wore a vest containing about 15 pounds (7 kilograms) of explosives, a senior Pakistani police official said. Watch witnesses describe the attack »
The Taliban claimed responsibility for the attack.