The Brazilian presidential candidate Eduardo Campos, 49, has died in a plane crash, party members and local officials say.

The plane carrying Mr Campos came down in bad weather in a residential area of the port city of Santos, in Sao Paulo state.

Four other passengers and the two pilots were also killed.

President Dilma Rousseff has declared three days of national mourning and cancelled campaign events.

"The whole of Brazil is in mourning," Ms Rousseff said in a statement.

"We lost a great Brazilian today, Eduardo Campos. We lost a great comrade," she added, calling her rival a "great political leader".

Ms Rousseff's Vice-President, Michel Temer, also expressed regret over the death of Mr Campos, who had been running third in opinion polls for October's election.

He said there were "no words to describe the tragedy that has befallen Brazilian politics today".

"Eduardo Campos was a politician with principles and values passed down through his family and carried with dignity and honour throughout his career in parliament and the executive," he added in a statement.

The BBC's Wyre Davies in Rio de Janeiro says Brazil has been rocked by the news.

Brazilian television broadcast a continuous loop of images of the wreckage, a smouldering pit between buildings of several storeys.

Mr Campos' family had actively opposed Brazil's military rule (1964-1985).

A married father of five children, he served two terms as governor of the north-eastern Pernambuco state.

Source: BBC