MOSCOW -- Speaker of the Russian State Duma, or lower house of parliament, Vyacheslav Volodin said on Friday that Nicolas Maduro's victory in the Venezuelan presidential elections was legitimate.

"(Venezuelan) citizens voted for the current President Maduro ... According to our observers, he won legitimately, although by a small margin," Volodin wrote in his Telegram channel.

Venezuela's presidential elections were held last Sunday. On Monday, Venezuela's National Electoral Council declared Maduro the winner with 51.2 percent of the counted votes.

A military officer in northern Aragua state was killed and 48 military and police officers were injured in the violent riots following Sunday's elections in Venezuela, the country's Attorney General Tarek William Saab said Tuesday.

Up to 749 people have been arrested for participating in the riots over charges of "incitement, obstructing public roads, hate crimes ... resisting arrest and, in the most serious cases, terrorism," said the attorney general at a press conference.

Maduro on Wednesday submitted an appeal to the Electoral Chamber of the Supreme Court of Justice to audit and certify the results amid calls for greater transparency.

Moscow has urged the Venezuelan opposition to concede defeat. Kremlin Spokesman Dmitry Peskov has warned third countries against supporting attempts to destabilize the situation in Venezuela.