In the worst incident, unknown armed men today killed at least 10 people when they fired indiscriminately on passengers of a mini-bus.
Sindh Information Minister Sharjeel Memon said the armed men intercepted the coaster near Banaras Chowk neighbourhood and shot indiscriminately on the passengers, killing at least 10 and wounding 20 others.
He said the attackers escaped in the narrow bylanes. In all, some 25 more people were reported killed since last night, bringing the death toll in the last three days to around 70, with scores injured amid growing tensions between the ruling PPP and its estranged ally Mutthaida Qaumi Movement (MQM).
A six-year-old girl and a fruit vendor were killed in the worst-hit Qasba Colony area of Orangi Town due to firing.
Five people were hijacked and killed in a public transport bus in Gulshan-e-Iqbal area early yesterday.
The violence is blamed on political and ethnic differences between the the Pashtun-dominated Awami National Party (ANP) and the Urdu speaking MQM, which has considerable influence in Pakistan's largest city.
Panic and fear gripped Pakistan's financial hub after the MQM announced a series of peaceful protests over the violence, particularly in Orangi town which has been the worst hit.
Amid anticipation that the MQM would announce a two-day strike to protest the killings, petrol pumps and shops downed their shutters since afternoon and people rushing back home.