By Stephen Gibbs BBC News, Havana

Castro's army defeated the invasion in less than 72 hours

Cuban President Fidel Castro has marked the 45th anniversary of the failed US-backed invasion of the island, known as the Bay of Pigs.

Havana's Karl Marx theatre was packed with hundreds of veterans who defended Cuba in the operation in 1961.

On 17 April that year, about 1,500 CIA-trained Cuban exiles invaded the bay on the southern coast of Cuba.

Mr Castro's army vastly outnumbered the exiles and President John F Kennedy decided not to provide air support.

Elian in audience

A huge banner in the Havana theatre declared that the battle was Yankee imperialism's first military defeat in the Americas.

The main event of the evening was a speech by the man who led Cuba's defence then and has led the country ever since.

President Castro drew parallels between the Bay of Pigs and what he portrayed as continued American aggression around the world, particularly in the Middle East.

The 79-year-old leader also swapped jokes with some of the elderly members of the audience.

"We might die old in years," he assured them, "But we will be young at heart."

Some of those attending the event were born well after the 1960s.

Among them was Elian Gonzalez, the young boy shipwrecked when he left Cuba on a raft six years ago and who was later subject to a bitter custody battle between his relatives in Cuba and the US.

Also listening to the speech was a large group of Cuban students who are studying social work.

They have been recruited by the Cuban leadership as the frontline in an ongoing battle against corruption across the country.