Moscow is speeding up issue of Russian passports to personnel of Ukraine's elite police force Berkut which was recently disbanded by the interim administration in Ukraine, amid rising Crimea tensions.

The Russian foreign ministry said it has ordered its diplomatic mission in Crimea, the autonomous Russian-dominated region in Ukraine which is turning into a key battleground of the crisis, to issue passports and citizenship cards to Berkut personnel.

The ministry said in a post: "The Russian consulate in [Crimean capital] Simferopol has been instructed to take all necessary measures to start issuing Russian passports to officers of the Berkut unit."

The 4,000-strong Berkut, well-trained and specialised in riot control operations, was disbanded by Ukraine's caretaker government for taking part in the bloody crackdown on anti-government protests, which led to the overthrow of Viktor Yanukovich as president.

Those who obtain Russian citizenship will also be given career opportunities in the Russian regions of Ukraine suggesting that they will be able to participate in operations on behalf of Moscow.

"If needed, the region can accept, accommodate and provide social, rehabilitation and other help for Berkut officers and their families," the governor of Russia's Astrakhan region has said.

The move is expected to be widely welcomed by the riot police forces that have been facing abuses and threats since the takeover by the interim government.

"The people who have come to power do not need us; to them, we are enemies. We have been threatened, they want to execute us. Of course, in such conditions we will be glad to receive any kind of protection," a Crimea-based Berkut police official told the Russian news outlet RIA Novosti.

Moscow's latest move comes when Russia is reportedly bolstering its military presence in a bid to secure its interests in Crimea, a move dubbed as "armed invasion" by Ukraine.