The blast came just two weeks after a suicide bomber struck near the Pakistani capital, killing four people, including three Chinese nationals.
The blast took place in the commercial area of Sadar on Thursday night.
Several of the injured were in critical condition, according to authorities, and “most of them were injured by explosive ball bearings,” said Shahid Rasool, medical superintendent at Jinnah Postgraduate Medical Center (JPMC), where all the injured have been transferred, according to Xinhua.
A state of emergency has been declared at all government hospitals in Karachi, Geo TV reported.
According to Deputy Inspector General (DIG) South Sharjeel Kharal, several vehicles were also damaged in the blast and windows of nearby buildings were shattered. Kharal mentioned that two government employees were among the injured.
According to Bomb Disposal Squad (BDS) officials, an explosive device was placed in the bicycle carrier which was detonated using a time device.
“The bomb was made locally and used about 2 to 2.5 kilograms of explosives,” BDS said.