Police struggled to keep apart rival groups in Ukraine’s largely Russian-speaking Crimea regional capital Simferopol yesterday, where the regional parliament was holding a crisis session.

At least one person was killed as several thousand Muslim Crimean Tatars rallied outside the regional parliament building in support of Ukraine’s coup leadership, waving Ukrainian flags and chanting: “Ukraine is not Russia” and “Allahu Akbar.”

They were attempting to prevent any discussion of the legitimacy — or lack of it — of the machinations in Kiev and were fearful that Crimeans would raise talk of separation from the pro-EU west of the country.

But they were confronted by ranks of Russian-speaking demonstrators who called for stronger ties with Russia and waved Russian flags, blocking the way into the parliament building itself.

Protesters shouted and punched each other in ongoing scuffles, as police struggled to keep the two groups apart.

Tatars fear that the country's mainly Russian-speaking east will not recognise the interim authorities dubious claims to legitimacy.

“We are ready to fight for Ukraine and our European future,” said Tatar protester Nuridin Seytablaev.

But nearby, separated by police lines, rival protester Anton Lyakhov declared: “Only Russia can defend us from fascists in Kiev and Islamic radicals in Crimea.”

Russian President Vladimir Putin has ordered an immediate test of combat readiness of troops in central and western Russia.

But Russian Federation Council speaker Valentina Matvienko dismissed claims that Russia could conduct a military operation in Ukraine.

“That scenario is impossible,” she said.

“Russia has been stating and reiterating its stance that we have no right and cannot interfere in domestic affairs of a sovereign state,” said Ms Matvienko, a close Putin ally who was born in western Ukraine.

“We are for Ukraine as a united state and there should be no basis for separatist sentiments.”

Meanwhile, Kiev’s acting interior minister Arsen Avakov, a member of Yulia Tymoshenko’s Fatherland Party, ordered the disbandment of the 5,000-strong Berkut riot police force, claiming it was guilty of attacks on protesters.

Kiev’s pro-Western interim leaders were set to unveil their new Cabinet late yesterday in Kiev's Independence Square.