By Andrew Osborn
SEVASTOPOL, Ukraine, March 3 (Reuters) - The new head of Ukraine's navy has been in the job for less than a day, but, like his fleet and parts of his country, he is already under siege.
On Monday morning, Serhiy Haiduk told his men that his predecessor, who defected to the pro-Russian authorities in Crimea the previous day, was wanted for treason.
In the evening, he was holed up behind the crumbling white walls of his headquarters with some well-armed Russian soldiers and at least 200 angry pro-Russian activists at his gates.
Meanwhile, two warships - all that what was left of his fleet of around a dozen vessels - found themselves blocked in their Black Sea berths in Sevastopol by a Russian minesweeper.
"A Russian commander went aboard the Ukrainian ships for talks this morning. The ships tried to leave but couldn't and now you can see that Russian minesweeper is blocking them," a local tour guide, who shows people round the port, told Reuters.
Sevastopol is home to Russia's Black Sea Fleet and, since the 1991 collapse of the Soviet Union, the far smaller Ukrainian navy has been based here too.
The two fleets have for years enjoyed friendly relations, but Moscow's decision to use troops to secure various military objectives in Crimea has strained ties to breaking point.
In Sevastopol town, outside the Ukrainian naval base, two young men who pro-Russian activists described as Russian soldiers and who were wearing camouflage fatigues used by Russia's military, had taken up position in front of the gates.
Wearing balaclavas and shaking their heads every time somebody tried to film them, one held a heavy machinegun and the other a Kalashnikov assault rifle.
Further, along the base's perimeter in what seemed to be an unfinished building, at least six more soldiers looked on.
A man who declined to give his name said the pro-Russian crowd wanted Haiduk to come out and say he was with the people and not with the authorities in Kiev, the Ukrainian capital.
"He's hiding in there. The soldiers inside don't need to surrender their weapons, but we need to know they are with us" he said.
Protesters, some of them from the local pro-Russian 'Russian Bloc' party, waved Russian flags and the flag of the Russian Navy, along with some Soviet-era military banners.
On the walls of the base they had erected two posters. One read "Fascism will not pass", while the other called on the Ukrainian military to "support the people".
The smell of alcohol hung in the air.
As the Russian national anthem blared out, two protesters smiled as they held fighting dogs that strained at the leash.
"We just want the guys inside to cross over to the people's side," Vladimir Branec, a 38-year-old mechanic, said. "This is a peaceful meeting." He added with a laugh: "They've already given up twice and then changed their mind."
The Ukrainian soldiers must renounce the oath they had made to Ukraine and swear loyalty to the people of Crimea, he said.
If Haiduk was thinking of emerging, he would have struggled to get far. Pro-Russian protesters had parked three cars right in front of the gates, effectively blockading the base.
Earlier in the day, Haiduk had lined his men up and told them that his predecessor, Rear Admiral Denys Berezovsky, had been relieved of his post and was facing treason charges.
Witnesses said the Ukrainian sailors had spontaneously broken into the national anthem and some had wept at the news.
As darkness fell and pro-Russian activists continued their "meeting", a young man whose brother - a Ukrainian sailor - was stuck inside, challenged the protesters to explain themselves.
"Why are you doing this?" he asked. "The Russian soldiers are already looking after security. You don't need to do this."
A man who wanted to be identified only as Mikhail, a 34-year-old businessman, said the Russian soldiers were protecting the base to ensure that "provocateurs" did not start a conflict.
"They are guarding the Ukrainian servicemen from provocations," he said. "If they leave ... any car could approach and shoot the place up, and if some 'for sale' correspondent filmed it and someone had a Russian flag in their hand, it would be all over the media and the international community would force the Russian fleet from here." (Editing by)