ISLAMABAD, Pakistan (CNN) -- A suicide bomber on a motorcycle struck a Pakistani Defense Ministry bus Thursday, killing at least one person and wounding 29 others, Rawalpindi police and medical officials said.
The bus was carrying ministry employees, police official Rao Muhammad Iqbal said.
Iqbal initially told CNN that six people were killed, but later said on Pakistani TV that only one person died in the attack.
Dr. Khaled Iqbal, medical superintendent of Rawalpindi's district hospital, also said one person died and 29 others were injured. Six sustained critical injuries, Iqbal said.
The suicide bomber drove the motorcycle into the gas tank of the bus, Rawalpindi regional police chief Nasir Durani said.
The attacker may have used a motorcycle because of increased police searches on cars throughout Pakistan.
Rawalpindi, located outside Islamabad, is where Pakistan's military is headquartered.
It is where former Prime Minister Benazir Bhutto was assassinated in December 2007.
In a separate attack on Thursday, someone threw a hand grenade in a market near the city of Dera Ismail Khan in Pakistan's North West Frontier Province, killing one person and injuring four others, police official Saeed Khan told CNN.
It is the latest attack to strike Pakistan in the wake of its military offensive against the Taliban, centered in the Swat region of North West Frontier Province. At one point, the Taliban offensive came within 60 miles of the capital, Islamabad.
CNN's Jonathan Wald in Islamabad, Pakistan contributed to this report.
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