At least three people were killed and 13 others wounded when they attacked a national guard base in Mariupol, a city in southeastern Ukraine, Interior Minister Arsen Avakov said Thursday.

"There are no casualties among the Interior (Ministry) troops. According to the preliminary figures, there are three dead and 13 wounded among the attackers. There are 63 under arrest," Avakov said in a post on his Web site.

About 300 people attacked the national guard base in Mariupol, a city of about 500,000, on Wednesday night with Molotov cocktails, the interior minister said.

The mob fired shots at guardsmen, who first fired warning shots and later at the attackers, Avakov said.

Russian President Vladimir Putin, meanwhile, said Thursday that he was hopeful that the talks in Geneva among Ukraine, Russia, the United States and the European Union would produce positive results.

"I have high hopes that the diplomatic efforts being made in Geneva will bear fruit and allow our Ukrainian colleagues and friends ... to find a consensus that guarantees the interests of all the citizens of the country, including the Russian-speaking population of the southeast," Putin told reporters.

Pro-Russian separatists on Wednesday declared a republic in Odessa, a region in southern Ukraine on the Black Sea, following the lead of separatists in the eastern region of Donetsk, the epicenter of the uprising against authorities in Kiev.

Separatists declared a people's republic in the Donetsk region, where they have seized government buildings in several cities, on April 7.

Ukraine's acting president, Oleksandr Turchynov, issued an ultimatum on Sunday to the separatists, ordering them to lay down their arms and leave occupied government buildings in the southeastern region of the country by 9:00 a.m. on Monday.

Turchynov said Sunday that he would use the army to restore order and signed a decree guaranteeing that those complying with the ultimatum would not be prosecuted as long as they did not injure anyone. EFE