A powerful bomb went off near Guru Mandir in Karachi on Wednesday, killing three people and injuring several others.

Police say that Bilal Sheikh, Chief Security Officer of President Asif Ali Zardari, is also among the dead.

Eleven others were injured in the explosion which took place in the heart of the city, located less than a kilometre from the Qauid's mausoleum.

“Three people, including the president’s chief security officer Bilal Sheikh, were killed in the bombing,” said Superintendent Police Usman Bajwa.

Bilal Sheikh was the chief security officer of the president and well as an active worker of the Pakistan People’s Party, the ruling party in Sindh province.

A spokesman for the Bilawal House, the residence of President Zardari in Karachi, confirmed Sheikh’s death.

Bajwa said the attack appeared to be a suicide bombing. “Bilal Sheikh’s vehicle was the target of the attack,” he said.

Officials said the wounded included six police officers and an FIA personnel. The injured were shifted to a local hospital where a state of emergency was imposed.

The explosion comes on the eve of start of the holy Muslim month of Ramazan, due to be observed in Pakistan from Thursday.

Bomb Disposal Squad (BDS) officials have reached the incident site and investigating the genre and further details of the attack whether it is suicide or planted.

Heavy contingents of security forces including Police and Rangers have been deployed who cordoned off the whole area.

President Asif Ali Zardari expressed profound grief at the killing of Bilal Sheikh in the blast.

Sindh Chief Minister Qaim Ali Shah strongly condemned the blast.

In a statement, Prime Minister Nawaz Sharif denounced the blast, which killed the chief security officer of President Zardari and his guards.

Both the President and the Prime Minister have directed the authorities concerned to provide best medical treatment to those injured in the blast.