A Pakistani government prosecutor said Friday he will challenge a court order granting bail to the alleged mastermind of the 2008 terror attacks in Mumbai.

A Pakistani government prosecutor said Friday he will challenge a court order granting bail to the alleged mastermind of the 2008 terror attacks in Mumbai.

A judge in an Islamabad anti-terror court granted bail on Thursday to Zaki-ur-Rehman Lakhvi, accused of masterminding the siege on India's commercial capital that left 166 people dead.

The court order drew swift condemnation from New Delhi, which urged the Pakistani government to appeal.

"I am completing all the legal formalities and then I will challenge this order in Islamabad on Monday," government prosecutor Mohammad Azhar Chaudhry told AFP.

The 60-hour assault on Mumbai was blamed on the banned Pakistani militant group Lashkar-e-Taiban (LeT).

Relations between the two nuclear-armed rivals worsened dramatically after the carnage, in which 10 gunmen attacked luxury hotels, a popular cafe, a train station and a Jewish centre.

Lakhvi remained in the high security Adyala prison in garrison city of Rawalpindi even after Thursday's court ruling.

"Today I am trying to get a copy of the written (bail) order and then I will file an appeal in Islamabad high court," Chaudhry said.

The court's ruling on Thursday came a day after Pakistani Prime Minister Nawaz Sharif vowed to crack down on terror groups in Pakistan, after Taliban gunmen massacred 148 people, mostly teenagers, at a school.

Sharif on Wednesday announced that a six-year moratorium on the death penalty would be lifted for those convicted of terror offences.

Indian Home Minister Rajnath Singh had said granting the bail was "very unfortunate".

"India has given enough evidence (against Lakhvi). We expect the Pakistan government to appeal at the earliest," he told journalists in Delhi.