In Pakistan, angry Shi'ite Muslims have clashed with police during funerals of 19 people killed in an apparent suicide bombing of a mosque Monday in Karachi.

Witnesses say police fired tear gas to disperse thousands of people who had gathered for the funerals in front of the mosque, where the deadly bombing took place Monday. Angry Shi'ite mourners pelted security officials with stones and ransacked nearby shops.

No one has claimed responsibility for the bombing, the second such attack against a Shi'ite mosque in Karachi in less than a month. Pakistani police say the latest attack may have been the work of a suicide bomber to avenge Sunday's assassination of a prominent Sunni leader in Karachi.

But Pakistani political analyst Hasan Askari says the recent violence in the country's largest city is in response to the government's crackdown on extremist Islamic groups to curb terrorism.

"The roots can be traced back to the conflict that exists in Pakistan between the government that is trying to control the militant Islamic groups and these groups are trying to assert their independence and trying to demonstrate that they can go ahead and do whatever they want to do," he said.

Karachi has been plagued with political and sectarian violence between extremist Sunni and Shiite groups, with more than 50 people killed during the past month.

Pakistan President Pervez Musharraf has condemned Monday's attack in Karachi as an act of terrorism and has promised to take tough actions to stem the bloodshed.

Addressing an international seminar in Islamabad, Mr. Musharraf expressed concern over growing number of terrorist attacks in and outside Pakistan, involving religious extremists.

"The unfortunate reality is that both the perpetrators of the crime as well as the sufferers from it happen to be Muslims," he said.

The Pakistani leader has been the target of Islamic militants who are angry at his support of the U.S. led war on terrorism. Mr. Musharraf twice escaped attempts on his life in the past year.