The latest killings bring the toll to 27 since the fresh wave erupted on Friday, intensifying a surge of violence blamed on political, ethnic and criminal rivalries which has left scores dead so far this month.
Pakistan last week deployed hundreds of additional police and paramilitary troops onto the streets of the country’s largest city to try to quell the unrest.
The violence in Karachi has been blamed on supporters of the Muttahida Qaumi Movement (MQM), based among the Urdu-speaking majority, and the rival Awami National Party (ANP), which represents ethnic Pashtun migrants.
Sporadic gunfire echoed around the port city’s eastern districts of Malir, Khokhrapar and Landhi overnight, residents said. Most of the criminal gangs are believed to be hiding in the impoverished neighbourhoods.
“At least 16 people have died over the past 24 hours, they were victims of ethnic and sectarian violence,” city police chief Saud Mirza told AFP.
“We have rushed additional police force to the troubled areas and the situation has improved.
One senior police officer said that two mortar shells were fired in the clashes between rival activists.
The MQM last month quit the coalitions led by the main ruling Pakistan People’s Party that govern the country and the southern province of Sindh, of which Karachi is the capital. The ANP remains part of both coalitions.
The Human Rights Commission of Pakistan says 490 people were killed in targeted killings in Karachi in the first half of the year, compared to 748 in 2010.
Four days of unrest killed 95 people before troops took back areas of Karachi held by armed gangs on July 9.