A bomb blast at a huge gathering to mark the anniversary of the Prophet Muhammad's birth
has killed at least 40 people in southern Pakistan.
Many others were injured and it is feared the death toll will rise
after the powerful blast ripped apart a stage where religious leaders were sitting.
Tens of thousands of Sunni Muslims had been taking part in evening prayers in Karachi's Nishtar Park at the time.
Angry crowds later turned on the police saying they had not provided security.
Interior Minister Aftab Khan Sherpao said 40 people had been confirmed dead in the park blast and the number was likely to rise.
Hospital sources said the death toll had risen to at least 45.
No-one has claimed responsibility for the explosion at what was believed to be the biggest of such events being held in Pakistan.
Karachi has a history of sectarian and ethnic violence, but this is the first time in decades that a religious gathering celebrating the Prophet's birthday has been targeted, the BBC's Zaffar Abbas in Pakistan says.