Twin bomb blasts killed six people, including a young girl, in a crowded market area of Pakistan's southern port city Karachi Tuesday, police and hospital officials said.
Hours earlier a roadside bomb ripped through a passenger bus carrying Shiite Muslim pilgrims in the troubled southwest of the country, killing three.
In Karachi, Pakistan's financial capital, the two bombs went off three minutes apart in the crowded Hyderi Market during the evening rush hour, police officer Azam Khan said.
The first went off near a dustbin while the second went off in a parking lot, he said.
"We suspect the (second) bomb was planted in a car or a motorbike parked in the area," Khan said, confirming that six people were killed, including a nine-year-old girl, and more than 18 were wounded.
Karachi city police chief Iqbal Mehmood said he did not know who was responsible but a large device was discovered and safely defused in the same area last month.
The powerful blasts were heard several kilometres away, residents said.
"I was in my gift shop when we heard a mild explosion and then a huge one minutes later," 33-year-old shopkeeper Iqbal Rehman said.
"We rushed to the parking lot and saw some vehicles, including motorbikes destroyed. Several people were dead and injured.
"We started shifting the injured and the dead bodies in private cars and ambulances."
An AFP photographer said a motorcycle, which police identified as being used in the bombing, was completely destroyed. Cars and motorcycles were damaged and shop windows were blown in.
There were blood stains among the debris of shopping bags and victims' shoes and sandals.
Doctor Mohammad Shafqat, of the Abbasi Shaheed Hospital where the casualties were taken, said six bodies had been received, and the 18 wounded included three women and a child.
Bomb disposal squad official Abdul Hameed said the improvised explosive device that caused the blast was "carrying at least eight kilogrammes of explosives".
Ethnic, sectarian and politically-linked violence has killed at least 1,100 people so far this year in Karachi, according to Pakistan's leading human rights organisation.
Nobody has yet claimed responsibility for the blast which came as thousands of people rallied across the country to vent their fury at an anti-Islam film made in the US that has sparked protests across the Muslim world.
Earlier, three people were killed and about a dozen wounded when a roadside bomb hit a passenger bus carrying Shiite Muslim pilgrims in Mastung district, about 25 kilometres south of Quetta, the capital of insurgency-hit Baluchistan province.
Officials said the bus was returning from Iran after a pilgrimage. Nobody immediately claimed responsibility for the attack.
The oil and gas rich province, which borders Iran and Afghanistan, is plagued by sectarian violence, attacks by Taliban militants and a tribal insurgency.
Baluchistan has also been a flashpoint for violence between majority Sunnis and Shiites, who make up around 20 percent of the population.