Security officials guarding red zone
Security officials guard a road leading to Pakistan's parliament building after clashes with protestersReuters

Hundreds of protesters have gathered around Pakistan's parliament and other government buildings in Islamabad, demanding Sharia law in the country and martyr status for Mumtaz Qadri, who was hanged for killing Punjab governor Salman Taseer. The agitators pelted stones at police and set vehicles ablaze as officers fired tear gas to control violence.

Around 25,000 protesters marched from Garrison town of Rawalpindi to Islamabad in support of Qadri, who killed Taseer in January 2011 for challenging Pakistan's blasphemy laws and supporting a Christian woman convicted and jailed on blasphemy charges. Pakistan's law allows death sentence in certain cases for convicts.

According to Al Jazeera, the military was put on alert to protect a high-security area called the red zone. "Their main task will be to secure the zone that includes parliament, Pakistan Television, the Foreign Office, the Supreme Court and diplomatic enclave," said a report.

Protests began on 27 March to mark the 40th day of mourning of Qadri's execution, the Times of India reported, noting that protesters announced the unrest will continue until their demands were met. According to the report, the protesters are Sunni Tehreeks, a Pakistani Barelvi religio-political organisation that was formed in 1990.

They are demanding retention of blasphemy laws without any amendments; conversion of Qadri's jail cell into a national heritage site and a martyr status for him; the execution of Aasia Bibi, the blasphemy convict whom Taseer defended; removal of all non-Muslims from key government positions and unconditional release of all Tehreek members in jail on terrorism charges.

The Pakistan government reportedly banned media coverage of the protest march and agitations fearing it may cause further unrest in the country that is still reeling under the shock of the Easter blast, which claimed 65 lives and left hundreds injured. A Pakistani faction of the Taliban group has claimed responsibility for the blast at a public park in the eastern city of Lahore. The group targeted Easter celebrations by Christians.