Bomb rips through Pakistani gambling den - 22nd April 2011

An explosion has killed at least 15 people and injured more than 20 in Pakistan's biggest city.

Police say a homemade bomb exploded inside an illegal gambling den in the south of Karachi.

The explosion ripped through the crowded makeshift club in the Ghas Mandi district.

Police say it is unclear whether terrorists or rival criminal gangs were responsible for the attack.

Dozens of severely injured patrons were taken to nearby hospitals.

Police sealed off the site of the blast and used batons to push back large crowds of onlookers.

The southern port city of Karachi has been hit by escalating violence.

The city is Pakistan's commercial hub, but police have struggled to contain worsening violence, with more than 700 people killed in political, ethnic and gang murders last year.