Cuban President Raul Castro paid tribute to the late Venezuelan president Hugo Chavez on Wednesday, as ceremonies were underway to mark the first anniversary of his death.

Castro visited the Mountain Barracks, the military museum close to the presidential palace in Caracas that holds Chavez's remains, and laid a white rose on Chavez's grave.

Castro had arrived in Caracas earlier to take part in events to honour Chavez, who died aged 58 after a long fight against cancer. Presidents Evo Morales of Bolivia and Desi Bouterse of Suriname and Argentine Vice President Amado Boudou were in Caracas for the occasion, while Nicaraguan President Daniel Ortega was expected to arrive later.

Ceremonies to honour Chavez, who led Venezuela for 14 years, were set to start with a civilian-military parade. Visiting dignitaries were to attend a mass later at the Mountain Barracks.

Chavez tributes were taking place amid mass protests in Caracas and other Venezuelan cities against his hand-picked heir and successor, Venezuelan President Nicolas Maduro.

In three weeks of protests, 18 people have been killed and more the 250 have been injured.

In Cuba, where Chavez underwent cancer treatment for several months, tributes were also held.

Hundreds of people gathered by the statue of South American independence hero Simon Bolivar, who was born in Caracas, waving Venezuelan flags.

Traditional Cuban leader Fidel Castro described Chavez, after his death, as "Cuba's best friend."