FEODOSIA, Crimea -- Piling into buses, Ukrainian marines in Crimea began their journey back to the mainland Tuesday as former comrades saluted them from outside a base overrun by Russian forces.
It was a low-key exit from the eastern port of Feodosia, with fewer than a dozen friends or relatives bidding the marines farewell. A troop transporter bearing black Russian military plates trailed the bus as it pulled away.
Their departure came as Ukraine's defense minister stepped down Tuesday after harsh criticism for authorities' often-hesitant reaction to Russia's annexation of Crimea, which was formalized following a hastily organized referendum this month.
And while Ukraine struggles to handle its humbling at the hands of Russia, it is also dealing with the menace of seething Ukrainian nationalists angered by the police's killing of a leading radical.
So far, 131 marines have left Crimea, the defense ministry said. They are going to be stationed temporarily at a military barracks in the town of Genichesk in Ukraine's southern Kherson province, but their final destination is still unclear.
In an address to parliament, Defense Minister Igor Tenyukh denied that he had failed to issue clear instructions to troops but said he reserved the right to resign.
The order for Ukrainian troops to withdraw from Crimea was issued Monday, a week after many bases had already been stormed and seized by pro-Russian forces.
Lawmakers initially refused Tenyukh's resignation, but later accepted it and voted to appoint Col. Gen. Mykhailo Koval as his replacement.
About 4,300 Ukrainian servicemen and 2,200 of their relatives have asked to leave Crimea, Tenyukh said Tuesday. That means about two-thirds of the 18,800 military personnel and relatives that he said were stationed on the Black Sea peninsula were so far taking their chances in Crimea.
It was not clear how many of those troops had joined the Russian army or had simply demobilized.
Oleksandr Rozmaznin, deputy chief of operations for Ukraine's armed forces, has said navy troops will be redeployed in port cities along Ukraine's southern mainland -- in Odessa, Mykolaiv and Kherson.
Tenyukh has said accommodations for incoming soldiers were being prepared at boarding houses and other facilities in Kiev, the Ukrainian capital.
"We don't need to build any new garrisons or military encampments -- we are able to accommodate as many people as needed on the mainland," he said.
Ukraine's new government is struggling to consolidate control amid ominous signals of discontent from Right Sector, a radical nationalist movement that played a key role in the anti-government demonstrations which prompted President Viktor Yanukovych to flee to Russia in February.
One radical, Oleksandr Muzychko, was shot dead overnight as he was being detained by police, the Interior Ministry said Tuesday.
Muzychko, better known by his nom de guerre Sashko Bily, had become a lightning-rod figure in Russian attempts to portray Ukraine's interim government as dominated by radical nationalists. Moscow has cited the alleged influence of nationalist groups like Right Sector to justify its hasty annexation of Crimea, which has a large Russian majority.
However, many in Ukraine downplay Right Sector's importance and the group has no posts in the new government. Police say Muzychko was being sought for organized crime links, hooliganism and threatening public officials.
But Right Sector leader Dmytro Yarosh lashed out at the killing.
"We cannot silently watch as the Interior Ministry carries out active anti-revolutionary activities," Yarosh said. "We demand the immediate resignation of Interior Minister Arsen Avakov."
The Right Sector also demanded the arrest of the head of the Sokol special forces.
Amid the country's political turmoil, Ukraine's economy is in a dire state and representatives from the International Monetary Fund have been holding talks with the new government for weeks on the terms of a potential bailout.
Officials in Moscow, meanwhile, warned Kiev that the country's new government may have to pay more for Russian gas, the main bulk of Ukraine's energy mix.
President Vladimir Putin's spokesman, Dmitry Peskov, said a gas discount that Russia had previously given Ukraine was linked to Russian Black Sea fleet's lease deal in Crimea. Now that Crimea is part of Russia there's "no reason for the discount," Peskov said.
But he added the Russian natural gas giant Gazprom would have to set the new price for Ukraine.
In November, Russia agreed to help prop up Yanukovych's teetering government by selling Ukraine gas at $268.5 per thousand cubic meters, but that discounted price has since been scrapped.
Ukraine's Energy Minister Yury Prodan said Tuesday that Kiev would pay Gazprom no more than $387 per thousand cubic meters for gas in the next three months.
The U.S. and the EU have placed sanctions on Russia for annexing Crimea, and NATO member Norway on Tuesday suspended joint activities with Russia's military. But Russia has so far shrugged off the sanctions, including being tossed out of the elite, two-decade-old coalition known as the Group of Eight developed nations.
-- By ADAM PEMBLE and PETER LEONARD
Leonard and Yuras Karmanau reported from Kiev. Nataliya Vasilyeva in Moscow and Karl Ritter in Stockholm contributed to this report.