As a new regime consolidated its grip over power in Kiev on Sunday, calls for secession in the pro-Russian south of Ukraine were growing louder.

At a protest attended by thousands in the port city of Sevastopol on Ukraine's Crimean peninsula, the crowd voted to establish a parallel administration and civil defence squads.

Demonstrators waved Russian flags – there was not a Ukrainian flag to be seen – and chanted "Russia, Russia, Russia" during the gathering.

"Sevastopol is a Russian town and will always be a Russian town… we will never surrender to those fascists in Kiev," said Anatoly, who was handing out Russian flags and declined to give his surname. "The struggle is only just beginning."

The largely Russian-speaking eastern and southern regions of Ukraine have been shaken by events in the Ukrainian capital over the last week that have led to the toppling of President Viktor Yanukovych.

Nowhere in the country is a Russian heritage stronger than in Crimea. The peninsula was officially a part of Russia until 60 years ago when the Soviet leadership transferred it to Ukraine.

Even today the Kremlin retains significant influence in the popular holiday destination for wealthy Russians, and Moscow leases naval bases in Sevastopol for its Black Sea fleet.

"We are not like the Kievans, we will not give up," said Olga, a pensioner in the crowd on Sunday.

"We hoped there wouldn't be a split in the country, but if a fully Bandera regime emerges in Kiev then we will be a part of Russia," she added, using a controversial term for the opposition from the name of a nationalist leader who fought against both the Nazis and the Soviets during the Second World War.

Amid fears that the new leadership in Kiev will soon fire the local government, demonstrators elected a new city leader, Aleksei Chaly, who vowed to defend Sevastopol.

Protesters also voted to set-up self-defence squads – a fledgling militia that would mirror those established in pro-European Western Ukraine last week after Yanukovych's authority crumbled and locals ransacked police stations.

Speakers said that in a similar demonstration earlier in the day in the regional capital of Simferopol about 5,000 had joined such squads.

The response was likely to be much greater in Sevastopol where up to 200,000 people could be counted on, said Dmitry Sinichkin, president of the local branch of the Night Wolves motorbike group.

"Bloodshed is inevitable," added Sinichkin, who was dressed in black leather. The Night Wolves enjoy the patronage of Russian President Vladimir Putin and its leadership has close ties to the Russian Orthodox Church.

Speakers at the protest avoided direct calls for Russian intervention, but when the head of the city's administration said that the secession of Crimea could not be permitted he was booed from the stage.

Russian officials refrain from publicly stating their support for Crimean separatism, but Kremlin aide Sergei Glazyev described Ukraine last month as "schizophrenic" and said that Russia would support greater federalism.

In recent weeks local media have carried stories about intensive contact with Russian officials and Vladislav Surkov, the Kremlin's so-called "grey cardinal," was reportedly spotted in Crimea last week.

"Russia does not openly take part in encouraging separatism… but there are organisations which are financed through Kremlin structures," said Viktor Neganov, a local supporter of the uprising in Kiev who has just been appointed an adviser to the country's new interior minister.

Neganov suffered concussion and a bloody nose on Saturday when he was beaten by people greeting riot police returning from Kiev to Sevastopol in the wake of the fall of the Yanukovych government.

While Ukraine's riot police, or Berkut, are widely reviled by the opposition whose activists have battled them on the streets of Kiev for months, they were treated to a hero's welcome in Sevastopol, given flowers and embraced by locals.

There have been pushes for Crimean separatism several times since the fall of the Soviet Union, including during Ukraine's 2004 Orange Revolution, but analysts said that more was now at stake.

"It's easy to imagine Crimea calling a referendum and getting special status within the Ukraine," said Masha Lipman, an expert at the Carnegie Centre in Moscow. "The natural next step would be to secede."

There was little sympathy in Sevastopol for Yanukovych, who has fled Kiev and been denounced by many of his closest followers. His current whereabouts is unknown.

"I don't support Yanukovych because he has betrayed Ukraine," said Dmitry Kovalenko, 23, a student. "We need to unite with Russia."