Rehman was attacked by a suicide bomber outside a rally venue in Quetta, the capital of the restive Balochistan province, as at least two people were killed and 30 others injured.
The blast occurred when the Jamiat Ulema-e-Islam Fazl (JUI-F) chief was leaving after addressing the massive rally where over 20,000 of his supporters had gathered, officials said.
"I was the target of the attack but God saved me. My vehicle was bullet and bomb proof so I survived but the vehicle has been destroyed," Rehman said.
Banned militant group Jundallah claimed responsibility for the attack.
Jundallah has in the past also carried out attacks on other politicians and government officials.
According to the bomb disposal squad, six to eight kilogrammes of explosives were used in the attack.
The injured were shifted to Civil Hospital, where six were said to be in a critical condition.
In a separate incident, at least three people were killed and 14 others injured in a roadside bombing on Qambrani Road here, police said.
Unidentified gunmen opened indiscriminate fire following the blast that hit the FC vehicle.
No group has claimed responsibility for the attack but Baloch nationalists often target security forces in the province.
Before this assault, unidentified gunmen today killed at least nine Shia Muslims, members of the ethnic Hazara community, here.
The victims were travelling in a bus when gunmen attacked them in Hazar Ganji area of Quetta.
Senior police officer Qureshi told reporters that nine members of the Hazara community were killed and many injured in the attack.
The attackers escaped after the attack and police was searching for them.
Nobody took responsibility of the attack but Sunni militant groups such as the Lashkar-e-Jhangvi (LeJ) regularly target the Shia community.
