India's top court has halted the freeing of four more killers of former prime minister Rajiv Gandhi after a political uproar over a state government's plan to release them.

The Supreme Court in New Delhi on Thursday issued a temporary restraining order against releasing the four who are serving life in jail over Gandhi's assassination in 1991 by a female suicide bomber.

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Prime Minister Manmohan Singh last week rejected the Tamil Nadu state chief minister's move to set seven conspirators, including the four, free, saying it was against all principles of justice as the murder was "an attack on the soul of India".

The court last week blocked the release of three of the men convicted of plotting the assassination, after Singh's comments and his government's urgent legal action against the move.

Examining issues

Chief Justice P Sathasivam issued the new order on Thursday, after hearing the government's arguments against releasing the other four, saying he needed time to examine the issues.

"There are two questions before us. The first is which is the correct government to decide on remission for these convicts and the second is whether the right procedure is being followed," Sathasivam told the court.

Gandhi, whose widow Sonia is now president of the ruling Congress party, was targeted by the Sri Lankan Tamil Tigers while he was campaigning in the southern state in May 1991 before an election.

His killing was seen as a retaliation for a 1987 Indian government pact with Sri Lanka to disarm the Tamil fighters. India later withdrew its troops deployed to the island after losing 1,200 soldiers at the hands of the rebels.

Critics have said Chief Minister J Jayalalithaa's surprise decision was motivated by a desire to woo ethnic Tamil voters in her southern state for her regional party at the general elections due by the end of May.

Source: Agencies