Tripoli, May 1 (IANS) Saif al-Arab Gaddafi, the youngest son of embattled Libyan leader Muammar Gaddafi, was killed in a NATO airstrike, Xinhua reported.

Government spokesman Mossa Ibrahim said that Saif, 29, and three of Gaddafi’s grandchildren were killed during a NATO raid on their residence.

The Libyan leader and his wife were present in the house when it was attacked but they are safe, he added.

He said it was an attempt to kill their leader.

In a televised speech Saturday, the Libyan leader had presented a ceasefire proposal and urged the parties concerned to follow it. He also wanted the NATO forces to stop their attacks.

Gaddafi, who ruled the country for more than four decades, has refused to quit despite an armed revolt against his government.

The US, Britain and France launched airstrikes against Gaddafi’s forces March 19 after the UN Security Council passed a resolution to impose a no-fly zone over Libya and authorized ‘all necessary measures’ to protect civilians.