Both Houses of Parliament on Wednesday remembered the security personnel who were killed while defending the Parliament in the December 13 terror attack in 2001.

Bharatiya Janata Party's Lok Sabha members demanded that Mohammad Afzal Guru, convicted of being the brain behind the attack, be hanged immediately.

The Supreme Court had ordered that Afzal be hanged on October 20, but a mercy petition pending before President APJ Abdul Kalam [Images] has delayed the hanging.

12 people, including five Delhi police personnel, were killed in the attack.

"Let us rededicate ourselves once again to protect the unity, integrity and sovereignty of our country," Lok Sabha Speaker Somnath Chatterjee said.

Members observed a minute's silence in memory of the departed. In the Rajya Sabha, Chairman Bhairon Singh Shekhawat praised the security personnel for foiling the attack.

When Deputy Leader of Lok Sabha Vijay Kumar Malhotra raised the Afzal issue, the Speaker asked the BJP members not to disrupt proceedings and said the House deeply mourned the death of those killed in the attack.

The Rajya Sabha was adjourned during Zero Hour amidst uproar as the BJP-Shiv Sena combine demanded Afzal's immediate hanging.

The Shiv Sena-BJP combine's protest led to the house being adjourned till 1400 hours.

The unrelenting opposition members trooped into the well repeatedly shouting slogans "Afzal ko fansi do (hang Afzal) and Sansad par hamla nahin chalega (attack on Parliament will not be tolerated)" which was countered by the Congress, RJD and Left members.

The uproar reached a high decibel when Home Minister Shivraj Patil cited cases like Rajiv Gandhi assassination where clemency petitions were kept pending for years.

His statement that in the last ten years mercy petitions have taken six to seven years before a decision could be taken angered opposition benches, which demanded Afzal's immediate hanging.

When BJP members said the Gen Vaidya murder case was decided very quickly, the home minister retorted citing the decision on mercy plea in the Rajiv Gandhi case.

Patil's assertion that the law will take its course in the Afzal case did not pacify agitated opposition members who kept shouting slogans at the top of their voice.

Rejecting opposition's contention that the government was not helping families of the martyrs who laid down their lives protecting Parliament House, the home minister said the financial assistance had already been provided.

On the charge of delays in allocation of petrol pumps to families of the bereaved, Patil said while the licensing issue has been sorted out, the problem was with allocation of land and that too would be resolved.

Deputy Chairman R Rahman Khan reminded the government that last year too the issue figured in the House and wanted that it should be done soon.