AKIPRESS.COM - Three protesters were killed and more than a dozen were wounded as they tried to overrun a National Guard base in east Ukraine last night, Daily Mail reported.

A crowd of about 300 armed attacked the base in the Black Sea port of Mariupol with Molotov cocktails late last night, but were repelled by troops of the interim government in Kiev.

Acting Interior Minister Arsen Avakov said 63 people were arrested over their part in the attack and that most of those taking part had been disarmed.

The latest confrontation in eastern Ukraine, where groups opposed to the new regime came as U.S. President Barack Obama boasted that U.S. troops were “superior”.

Speaking to CBS News, Obama said of Russia: “They are not interested in any kind of military confrontation with us, understanding that our conventional forces are significantly superior to the Russians.”

Speaking at the parliament this morning, acting President Oleksandr Turchynov said the protesters attempted to storm the base three times and carried automatic weapons.

The skirmish come after the Ukrainian government announced an operation to retake control of Slavyansk and other cities in the Ukraine's east.

The protesters, who the West says are backed by Russian forces, have taken control of police stations and administrative buildings in at least 10 towns in the region, including Mariupol near the Russian border.

There are also fears in the West the Kremlin might use “the instability in the predominantly Russian-speaking region as a pretext for military intervention.”

Today, Russia's president Vladimir Putin dismissed claims that Russian special forces are in eastern Ukraine as “nonsense”.

Speaking in a televised call-in show with the nation, Putin said that people in eastern Ukraine have risen against the authorities in Kiev ignoring their rights and legitimate demands.

He said that the government's decision to use the military to uproot the protests in the east was a crime.

The latest unrest came as diplomats from Ukraine, the U.S., the European Union and Russia prepared to meet Thursday for the first time over the crisis that threatens to the stability of the new government in Kiev.

With Ukraine struggling to contain the protests, the Obama administration has said it is readying additional sanctions against Moscow and a boost in aid for the Ukrainian military in the coming days.