The Supreme Court Thursday upheld the death sentence of Mohammad Afzal -- a key accused in the 2001 attack on Indian parliament that jolted the nation - while letting Delhi University teacher S.A.R. Geelani off the hook.

The court also commuted the death sentence of another accused, Shaukat Hussain Guru, to 10 years imprisonment and Rs.25,000 fine, stating he was not a part of the criminal conspiracy behind the parliament attack.

The court upheld the acquittal of Geelani and Navjot Sandhu alias Afsan Guru (Shaukat Hussain's wife) by the Delhi High Court in 2003.

Delhi Police had appealed to the apex court against the high court verdict freeing Afshan and Geelani of the charge of plotting the audacious attack on the lawmaking institution of the country.

Five gunmen breached the parliament complex on Dec 13, 2001 and were killed in a gun battle with security forces even as 300-odd MPs were holed up inside the main parliament building.

Nine innocent people were killed in the incident that was believed to have been masterminded by Pakistan-based terror outfit Jaish-e-Mohammad.

A bench comprising judges P.V. Reddy and P.P. Naolekar, while imposing death sentence on Afzal, described the parliament attack as "one of the rarest of rare cases warranting imposition of capital punishment".

The bench said the parliament attack had shaken the unity, sovereignty and integrity of the nation. "The elected representatives and constitutional authorities were attacked with explosives and the entire country came to a standstill by this diabolical incident."

While upholding the acquittal of Geelani, the court observed that there could be suspicion about his knowledge of the conspiracy in the way he rejoiced while the incident was taking place.

But in the absence of concrete and unimpeachable evidence he could not be convicted on mere suspicion, the judges felt. The same was the case with Afsan Guru, the court said.

Regarding Shaukat Hussain, the court said there was no evidence to link him to the actual conspiracy, but he was aware of his cousin Afzal's involvement in the attack as well as its entire plan and design.

By suppressing and not informing the police or magistrate about the conspiracy, Hussain had waged a war against the nation, for which he deserved to suffer imprisonment for 10 years, noted the bench.

A trial court had convicted Afzal, Shaukat Hussain and Geelani to death and awarded five years' imprisonment to Afsan Guru.

The Delhi High Court on Oct 29, 2003, had confirmed the death sentence of Mohammad Afzal and Shaukat Hussain and acquitted both Geelani and Afsan Guru.