The Pakistani Taliban claimed responsibility on Saturday for twin bomb attacks targeting Shiites in Karachi overnight that killed at least six people and wounded 35 others.
Shahidullah Shahid, a spokesman for umbrella group Tehreek-e-Taliban Pakistan (TTP), said that the attacks in Pakistan's largest city were carried out in revenge for violence in Rawalpindi on November 15.
He said the attacks were aimed at Shiites in Karachi, and vowed further violence.
"It was to avenge the Rawalpindi incident, we will carry out more such attacks to avenge the killing of Sunnis," Shahid said by telephone from an undisclosed location.
Fighting erupted in the garrison-city of Rawalpindi, which neighbours the capital Islamabad, earlier this month when a procession by Shiite Muslims to mark the most important day of the mourning month of Muharram coincided with a sermon at a nearby Sunni mosque.
The groups clashed with each other, TV cameramen and security forces. Officials said 11 people were killed and more than 60 injured while a Sunni mosque and seminary and an adjacent cloth market were burnt, with Sunni groups blaming Shiite protesters.
Thousands of people in major cities across Pakistan, including Karachi, protested amid high security on Friday after Sunni groups called for demonstrations against the Rawalpindi violence.
Thousands of people in major cities across Pakistan, including Karachi, protested amid high security on Friday after Sunni groups called for demonstrations against the Rawalpindi violence.
The explosions overnight in Karachi Friday took place within minutes of each other in the city's bustling, predominantly Shiite neighbourhood of Ancholi.
"At least six people were killed and some 35 wounded. Four among the dead were Shiite," senior police official Javed Odho said in Karachi, updating an earlier report of five killed and 18 injured.
Karachi, a city of 18 million people which contributes 42 percent of Pakistan's GDP, is rife with murder and kidnappings and has been plagued with sectarian, ethnic, and political violence for years.
The Pakistani Taliban dominates northwest Pakistan, but it has also penetrated the central Punjab province and has a strong presence in parts of Karachi.
The TTP has been behind hundreds of bomb and gun attacks that have fanned instability in Pakistan, killing more than 6,500 soldiers, police and civilians since 2007.