SIMFEROPOL, Ukraine — Several dozen armed men have stormed and seized the buildings of the legislature and the local government in Ukraine's Crimea region and raised a Russian flag over a barricade.

The men occupying the parliament building in the regional capital, Simferopol, early Thursday did not come out to voice any demands. They wore black and orange ribbons, a Russian symbol of the victory in World War II. The men also put up a sign saying "Crimea is Russia."

They threw a flash grenade in response to a journalist's questions.

Phone calls to the Crimean legislature rang unanswered, and its website was down. Refat Chubarov, a local leader of the Tatar community, wrote on his Facebook page early Thursday that the two buildings were taken overnight by uniformed men.

Russia has questioned the legitimacy of the new Ukrainian authorities after pro-Russian President Viktor Yanukovych fled last week, and it has accused them of failing to control radicals who threaten the Russia-speaking population in Ukraine's east and south, which includes the Crimean Peninsula.

Ukraine's new government was expected to be formally approved by parliament Thursday. It will face the hugely complicated task of restoring stability in a country that is not only deeply divided politically but on the verge of financial collapse.

Across Ukraine, the divided allegiances between Russia and the West were on full display Wednesday as fistfights broke out between pro- and anti-Russia protesters in the strategic Crimea peninsula. In the regional capital of Simferopol, some 20,000 Muslim Tatars rallying in support of Ukraine's interim leaders clashed with a smaller pro-Russian rally.

Russian President Vladimir Putin put the military on alert for massive exercises involving most of the military units in western Russia, and announced measures to tighten security at the headquarters of Russia's Black Sea Fleet on the peninsula.

The maneuvers will involve some 150,000 troops, 880 tanks, 90 aircraft and 80 navy ships, and are intended to "check the troops' readiness for action in crisis situations that threaten the nation's military security," Defense Minister Sergei Shoigu said in remarks carried by Russian news agencies.

The move prompted a sharp rebuke from U.S. Secretary of State John Kerry, who warned Russia against any military intervention in Ukraine.

Russia denied the military maneuvers had any connection to the situation in Ukraine, but the massive show of force appeared intended to show both the new Ukrainian authorities and the West that the Kremlin was ready to use all means to protect its interests.

While Russia has pledged not to intervene in Ukraine's domestic affairs, it has issued a flurry of statements voicing concern about the situation of Russian speakers in Ukraine, including in the Crimea.

The strategic region, where the majority of the population are Russian speakers, has strong ties to Moscow. It only became part of Ukraine in 1954 when Soviet leader Nikita Khrushchev transferred jurisdiction from Russia — a move that was a mere formality until the 1991 Soviet collapse meant Crimea landed in an independent Ukraine.

Igor Korotchenko, a former colonel of the Russian military's General Staff, wrote a commentary in a Russian online newspaper, slon.ru, saying "if illegal armed formations attempt to overthrow the local government in Crimea by force, a civil war will start and Russia couldn't ignore it."