KARACHI -?A Pakistani surgeon says the death toll from a massive car bombing in the southern port city of Karachi has jumped from 37 to 45 as more victims died overnight.

Dr. Jalil Qadir says that 146 people were also wounded in the Sunday evening explosion. At least 32 of them are still in serious condition.

The blast targeted members of the minority Shiite Muslim sect who were leaving a mosque when the bomb went off.

There was no immediate claim of responsibility but Sunni militant groups who do not consider Shiites to be true Muslims have carried out such attacks in the past.

The city shut down on Monday for a day of mourning.