Venezuela's former vice-president Nicolas Maduro has been sworn in as acting president hours after the state funeral of Hugo Chavez, according to BBC News.

The ceremony was led by National Assembly Speaker Diosdado Cabello in the capital, Caracas.

Chavez, who died on March 5 after a long battle with cancer, had named Maduro as his chosen successor.

However, the main opposition coalition boycotted Maduro's swearing-in, saying that it was unconstitutional. It argues that - under the constitution - the speaker of the National Assembly should be the one to take over as acting president.

The opposition leader, Henrique Capriles, called the move fraudulent.

After swearing in Maduro, Cabello said: "Venezuela will follow the route to socialism."

As acting president, Maduro is expected to call elections within 30 days.

Holding a copy of the Venezuelan constitution in his hand, Maduro announced at the National Assembly: "I swear in the name of absolute loyalty to Comandante [commander] Hugo Chavez that we will obey and defend this Bolivarian Constitution with the hard hand of the free people."