Raul Castro did not address the rally, Spanish news agency Efe reported.

There had been some suggestions he might announce economic reforms or more prisoner releases.

President Castro confounded critics last month by agreeing to free large numbers of political prisoners.

Many Cubans would have been hoping that Raul Castro would use the event to move on his long-awaited economic reforms, says the BBC's Michael Voss in Havana.

Average wages are barely $20 (£13) a month in the island's crippled state-run economy.

President Castro and other officials arrived for the ceremonies in the central city of Santa Clara early on Monday.

The main event was beside the mausoleum of Ernesto Che Guevara, the Argentine-born revolutionary leader who fought alongside the Castro brothers and was a close associate of Fidel.

President Castro handed out diplomas, while First Vice President Jose Ramon Machado Ventura delivered the keynote speech, Efe reported.

Mr Machado spoke of Cuba's support for Venezuela, currently mired in a diplomatic row with Colombia.

Venezuelan President Hugo Chavez cancelled a planned visit to Cuba in the light of the crisis.

Mr Machado also referred to what he termed "the visible recuperation" of Fidel Castro.

Fidel Castro, who turns 84 next month, has made six public outings over the past fortnight, the first since he stepped down to undergo major surgery in 2006.

However, despite rumours he might attend, there was no sign of the former president.

The annual 26 July rally marks the anniversary of the first battle of the Cuban revolution when Fidel, along with Raul, led an attack on the Moncada barracks.