Several hundred armed men in green camouflage, without insignia and carrying military-style automatic rifles, entered and secured areas of the civilian airport in Crimea’s regional capital of Simferopol early Friday.

Video taken at the scene showed the men patrolling inside the airport and standing guard outside. Flights continued to operate; no shots were fired.

In Kiev, Ukraine’s new interior minister, Arsen Avakov, said the armed men were Russian troops.

“What is happening can be called an armed invasion and occupation. In violation of all international treaties and norms. This is a direct provocation for armed bloodshed in the territory of a sovereign state,” Avakov said.

Avakov said troops from the Russian navy’s Black Sea Fleet, berthed principally at the Crimean port of Sevastopol, had also secured entrances to the Belbek military airport near the city.

1 of 44 Full Screen Autoplay Close Skip Ad × Protests in Ukraine: Activists clash as police force is given refuge View Photos Viktor Yanukovych, who was as ousted president of Ukraine but reportedly still claims himself its rightful leader, called on the Ukrainian military to resist any orders to interfere in pro-Russian protests in eastern and southern Ukraine. Tensions in Simferopol, the capital of the Crimea, were heightened Thursday when a band of armed men seized two government buildings. Caption Russian forces, already in control of much of Crimea, took possession of a ferry terminal in Kerch, in the eastern part of the peninsula just across a strait from Russian territory, according to reports from the area. The terminal could be used to send even more Russian troops into Crimea. Buy Photo Wait 1 second to continue.

“There is still no direct armed conflict. Diplomats should speak,” Avakov said.

A spokesman for the Black Sea Fleet denied the reports that its troops are involved in blocking the Belbek airfield, according to the Interfax news agency.

“No subdivision of the Black Sea Fleet has been advanced into the Belbek area, let alone involved in blocking it,” the spokesman said. “Given the unstable situation around the Black Sea Fleet bases in the Crimea, and the places where our service members live with their families, security has been stepped by the Black Sea Fleet’s anti-terror units.”

A Crimea news Web site, Argumenty Nedeli Krym, reported that the armed men carried M-4 assault rifles. “As journalists attempted to approach them, one of the servicemen warned that they would shoot to kill,” the Web site said.

At the Belbek airport, armed men and a military transport truck blocked the entrance. Whoever the men were, they did not appear to be civilian militiamen, but trained soldiers.

When a man who appeared to be a Russian officer with two bodyguards approached them, they spread out in defensive positions, squatted and waited for orders.

Dozens of troop transport trucks were scattered along the highway between Sevastopol and Simferopol.

In Moscow, Russian President Vladimir Putin broke his week-long silence on Ukraine with a mixed message. He ordered Russian officials to consult with other nations as well as the International Monetary Fund on means of financial assistance for Ukraine. He also said that efforts to maintain and promote trade between Russia and Ukraine should continue.

At the same time, Putin said Moscow would consider the possibility of sending humanitarian supplies to Crimea.

A Ukrainian legislator from the party of ousted pro-Russian president Viktor Yanukovych said Friday that the region, officially called the Autonomous Republic of Crimea, is not trying to secede from Ukraine.

Nestor Shufrych of the Party of Regions said the speaker of the Crimean regional parliament, Volodymyr Konstantynov, had told him by telephone that Crimea was interested only in broadening the terms of its current autonomous status.

“They are not asking for anything more,” Shufrych said. “The autonomous republic’s possible secession from our country is completely out of the question.”

The Ukrainian defense minister, Adm. Ihor Tenyukh, said he planned to go to Crimea later on Friday. The country’s foreign minister has requested talks with his Russian counterpart concerning Crimea.

“We have not received a reply from the Russian side so far,” said the acting foreign minister, Andriy Deshchytsa. “We are open to negotiations and wish an exclusively peaceful resolution of this problem.”

The revolutionary upheaval in Ukraine’s faraway capital has awakened the separatist dreams of ethnic Russians living on the Crimean Peninsula, where on Thursday pro-Russia gunmen who occupied the regional parliament building were met with an outpouring of support.

A group of men dressed in camouflage and armed with rocket-­propelled grenades entered the building early Thursday in the capital of Ukraine’s Crimea region, according to local reporters, then barricaded themselves inside and raised the Russian flag on the roof — a succinct answer to warnings from the United States and Europe that Ukraine must remain united and Russia must stand back.

In the freezing weather outside the parliament, separatist fever was running hot, as newly formed self-defense militias paraded under Russian military colors. They shouted thanks to their Soviet grandfathers who had fought against the Germans in World War II in the siege of nearby Sevastopol, a brutal 250-day campaign that left tens of thousands dead and the city in rubble.

“We want Crimea to return to Russia, pure and simple,” said Igor, a leader of a militia group composed of men who had fought in Afghanistan for the Soviet Union. Like other citizen militiamen, he declined to give his last name.

The demonstrations in Simferopol unnerved the newly appointed government more than 400 miles away in the capital, Kiev, where months of protests led to the ouster last week of Ukraine’s pro-Russia president, Viktor Yanukovych.

“Measures have been taken to counter extremist actions and not allow the situation to escalate into an armed confrontation” in the center of Simferopol, said Avakov, the interim interior minister.

By early morning, police had surrounded the Crimean parliament, but they did nothing to oust the men who had stormed inside. The occupation began to seem like a bit of a show; it was possible the gunmen had already departed. Police officers out front showed no fear of anyone inside and, instead, turned their backs to the building, taking frequent breaks to smoke cigarettes and drink tea.

Meanwhile, thousands of ethnic Russians — who make up about half of Crimea’s population — arrived to demonstrate. They issued a warning to recalcitrant lawmakers here to give in to the crowd’s No. 1 demand: a referendum on, at minimum, whether to allow the Crimean Peninsula — an autonomous state — to become an even more independent region, with its own leadership, which many demonstrators hoped would enshrine Russian language and culture.

Others who came to the parliament clearly wanted much more, calling for Crimea to return to the arms of the Russian motherland. “The criminals had their revolution in Kiev, and now we are having ours in Crimea,” said Alexandr, a member of another self-defense brigade. “We’re Russian, and we belong to Russia.”

For all their fervor, the crowds have not been huge, and it is hard to judge how much support the cause of separatism or a more independent region might have across Crimea. The government that was approved in Kiev on Thursday is stepping gingerly to avoid arousing passions. Pravy Sektor, the right-wing nationalist group, has said it will not send its members to the peninsula, to avoid confrontations.

Moscow has expressed displeasure with the upheavals in Ukraine, questioned the legitimacy of the new government and stressed that the West should keep out of the country’s internal affairs. But although Russian President Vladi­mir Putin on Wednesday ordered a large-scale military exercise in regions bordering other parts of Ukraine, triggering concern about a possible intervention, Russia has not signaled any desire to bring Crimea back into its fold.

Even so, members of separatist militias in Crimea, organized under a political party called the Russian Bloc, have begun to flex their muscles. They threw up checkpoints Thursday along the main highway between Sevastopol and Simferopol, operated by men in mismatched camouflage who stood before a hand-painted sign warning: “Those who approach with a sword will die by the sword.”

Until now, it could be illegal, and sometimes dangerous, to advocate separatism in Ukraine. Now it is all the rage, with groups here demanding that Russia reclaim territory that Soviet Premier Nikita Khrushchev gifted to the Ukrainian Soviet Socialist Republic in 1954. The Russian Black Sea naval fleet is berthed primarily in Sevastopol and supports 15,000 sailors and support staff.

Outside the parliament, voices in the crowd shouted, “Take us back!” as demonstrators unfurled a large Russian flag, sang patriotic Russian songs and denounced as “hooligans” the forces behind Yanukovych’s ouster.

Yanukovych, on the run for several days, appeared Thursday in Moscow, where he was apparently granted Russia’s protection.

Asked what he thought would happen next, a Russian Bloc politician from Sevastopol, Gennadiy Basov, said, “I have no idea.”

Basov said the pro-Russia militias in the Crimea “are prepared to defend our homes and families” from any forces sent by the central government in Kiev.

“Everything coming out of Kiev is illegal,” Basov said.

He and others outside the parliament, stoked on inflammatory Russian TV news shows that repeatedly broadcast images of protesters in Kiev hurling gasoline bombs and advancing with clubs, warned that if they let their guard down, hordes of “fascists” would descend on Crimea.

“They would come to steal, rape and kill,” one man said.

A woman who declined to give her name but described herself as “a Russian housewife from ­Simferopol” boasted that the demonstrators here were peaceful and unafraid to show their faces — ignoring for a moment that the protesters had gathered to support unknown gunmen inside the parliament.

In Kiev, Oleksandr Turchynov, Ukraine’s interim president, warned Moscow that any movement of military personnel off Russia’s naval base in Sevastopol “will be viewed as military aggression.”

Speaking in the Ukrainian parliament in Kiev on Thursday, Turchynov said, “Ukrainian enemies should not try to destabilize the situation, should not encroach on our independence, sovereignty and territory.”

Will Englund in Kiev contributed to this report.