Residents of the Pakistani city of Karachi were on Monday mourning the victims of a bombing in a Shiite neighbourhood which police said killed 52 and injured 127.

The explosion ripped through the Abbas Town area of the southern port city Sunday when a car packed with 150 kilograms of explosives was detonated with a timer, said police official Khalid Hussain by telephone.

“According to initial police reports about the incident, 52 people, including women and children, are dead while 127 were injured,” Mr. Hussain said.

No group has yet claimed responsibility for the attack.

The News International newspaper quoted the police chief of Sindh province, of which Karachi is the capital, as saying that the banned Sunni extremist group Lashkar-e-Jhangvi and the Taliban, also Sunnis, carried out the attack.

The Sindh government declared Monday as a day of mourning and the national flag was flying at half mast atop all official buildings.

The city of more than 18 million people came to a standstill Monday after various Shiite organizations announced a three-day period of mourning and political groups joined a strike call.

Local media reported that businesses were closed, public transport was off the roads and educational institutions were shut.

Karachi, the most populated city in the country, has seen an uptick in violence in recent years.

Attacks on Shias, who represent 20 per cent of Pakistan’s more than 180 million people, are rising. At least 228 people have died so far this year after two attacks in Quetta killed 176 people.