The explosion took place near the Aisha Manzil furniture market, where minutes earlier a rally of the Muttahida Qaumi Movement (MQM) and Tehreek-e-Minhajul Quran had ended.
DIG Asif Aijaz Shaikh said the explosive material was planted in a motorcycle. Several buses and other vehicles were also damaged in the blast.
The rescue teams and ambulances rushed to the affected area and launched the relief activities. The injured were shifted to Abbasi Shaheed Hospital and other nearby hospitals. Some injured are said to be in critical condition and death toll is feared to climb.
Meanwhile, the MQM chief Altaf Hussain has strongly condemned the blast, regarding it as a coward action.