At least 25 people were killed and 55 others injured when a twin bomb attack hit Pakistan's southwestern city of Quetta on Wednesday morning,?two local TV channels Express and Ajj reported.

According to the local media reports, the attack took place at about 9:00 a.m. local time on Wednesday in a government officials' work and residence area of Quetta, capital of Balochistan province in southwest Pakistan.

The first bomb, which reportedly contained an estimated 100 kilograms of explosives and was fixed to a rickshaw parked in front of the office of the Quetta District Commissioner Naseem Lehri, went off right before the office hour. The commissioner luckily escaped the attack as he had not reached the office when the blast occurred.

About five minutes later, as all the people were attracted to the first blast site, another suicide blast occurred inside a top local paramilitary officer's residence which stands just next to the commissioner's office.

According to eyewitnesses, the suicide bomber forced into the house of Deputy Inspector General Frontier Corps Brigadier Farrukh Shehzad with the help of two unidentified gunmen.

The gunmen opened fire at the bodyguards standing in front of the house and then ran away, then the suicide bomber entered the house and blew himself up while he was stopped by people inside the house, said eyewitnesses.

Shehzad, together with some of his children were seriously injured in the blast while his wife was killed right on the spot in the blast, said police sources.

Local watchers believed that the real target of the twin bomb attack is Shehzad who is said to be in charge of a recent operation which resulted in the arrest of a key al-Qaida member named Younis Al Mauritani in the suburbs of Quetta. The first bomb attack just served as a cover-up, they said.

An ID card later found by police from the pocket of the suicide bomber whose head had been recovered on the spot revealed that the suicide bomber is named Ahmad Gul aged at 21. He is from Kunduz province of Afghanistan. But the real identity of the suicide bomber is yet to be determined, said local police.

Since the killing of the former al-Qaida chief Osama bin Laden in Pakistan by the U.S. special forces on May 2, both al-Qaida and Pakistan Taliban have revenged the killing of bin Laden by launching a number of attacks at the Pakistani army, paramilitary forces and police.

Pakistani President Zardari strongly condemned Wednesday's twin bomb attack in Quetta and vowed to continue the fight against terrorists. He said the government was determined to root out extremism and terrorism from the country and would not be deterred by such acts of terror.