Bomb attacks in the Pakistani cities of Rawalpindi, Quetta and Karachi have killed at least 17 people, according to news report.
According to Reuters, a suicide bomber killed 13 people at Shia Muslim procession late Wednesday night in Rawalpindi, near the capital Islamabad, a day before the city hosts leaders from Egypt, Iran and other developing nations.
The blast ripped a hole in the walls of a Shia mosque and body parts were scattered at the scene.
However, hundreds of worshippers kept marching, beating their heads and chests, even when other explosive devices were found at the site.
Shias are celebrating the Muslim holy month of Muharram.
Al Qaeda linked Sunni militant groups have recently stepped up attacks against Pakistan's minority Shias, whom they regard as non-Muslims, Reuters wrote.
Earlier, two bomb blasts hit the southern city of Karachi, the first outside a Shia mosque, which killed at least two people.
TVNZ reported that a suicide bomber on a motorcycle rammed into a rickshaw driver, killing them both and wounding seven people.
A second explosion — at the scene of the first — killed one person and wounded 10, including journalists there to cover the news.
And a remote-controlled roadside bomb exploded in Quetta, hitting a military vehicle and killing at least three soldiers and two civilians, the BBC reported, citing officials.
The bomb detonated near a security vehicle escorting schoolchildren, wounding about 30 people, some critically.
No group has so far claimed responsibility for the attacks. However Pakistan's Army headquarters are based in Rawalpindi.
The Pakistani military has waged a long campaign against militants based in the country's northwest near the border with Afghanistan.
Also, Pakistan is on Thursday hosting a summit at which eight developing nations — Pakistan, Iran, Egypt, Turkey, Indonesia, Malaysia, Nigeria and Bangladesh — are to discuss trade and investment ties.
Several presidents have already arrived in Islamabad.
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