SEVASTOPOL, Crimea - Sailing into this Black Sea port Friday amid a jubilant spectacle of fighter jets and warships, President Vladimir Putin celebrated the return of Crimea to Russia as "historic justice" during a Victory Day display of military pomp and patriotism.

The gravity of the crisis gripping the rest of Ukraine was underscored by deadly clashes in the east, where fighting left bodies in the streets of the seaside city of Mariupol and the police station a smoldering ruin.

At least seven people were killed and dozens injured in the city, one of at least a dozen where pro-Russian insurgents are agitating to follow Crimea's lead in seceding from Ukraine.

Speaking before a cheering crowd of thousands on a triumphant first visit to Crimea since its annexation into Russia, Putin hailed the incorporation of its two million people as a "return to the Motherland" and a tribute to the "historical justice and the memory of our ancestors."

The Russian leader's visit to the Crimean port of Sevastopol, where Russia's Black Sea Fleet is based, came on Victory Day, which commemorates the defeat of Nazi Germany and is Russia's most important holiday. The trip was strongly criticized by the U.S., NATO, and Ukraine's Foreign Ministry, which said it trampled on Ukraine's sovereignty and international law.

Putin's two Victory Day celebrations - a massive show of military muscle in the annual Red Square parade in Moscow, followed by the extravaganza in Sevastopol - rubbed salt in the wounds of Ukraine's interim government in Kiev without ever once mentioning its name.

In Sevastopol, Putin rode a cabin cruiser-type boat past hulking warships, issuing greetings to their crews, as warplanes and helicopters swooped over the vast harbor. He then stepped onto land for a short address to the tens of thousands who had come to watch.

He expanded on the theme of righting a historic wrong with Crimea's return to Russia in a later address at a commemorative concert, saying Moscow respected other countries' interests and "we ask that all of them show regard for our legal interests."

Conquered by Russia in the 18th century under Catherine the Great, Crimea only became part of Ukraine in 1954, when Soviet leader Nikita Khrushchev transferred jurisdiction from Russia. The move was a formality until the 1991 Soviet collapse meant Crimea landed in an independent Ukraine. It remained under Ukrainian control until its annexation by Russia in March, following a hastily arranged referendum - moves condemned by the West and Kiev.

The violence in the port of Mariupol on the Azov Sea - along the main road between the Russian border and the Crimean Peninsula - was a clear sign of increasing unrest in eastern Ukraine.

The Donetsk region, which includes Mariupol, and the neighboring Luhansk region are to hold a hastily organized referendum Sunday on declaring sovereignty, a move likely to deepen the crisis between supporters of Ukraine's fledgling government and pro-Russia insurgents.

There were varying accounts of Friday's violence in the city of a half-million people. Ukrainian Interior Minister Arsen Avakov said about 60 gunmen attacked the Mariupol police station and were repulsed in an operation that killed one police officer and about 20 people he called "terrorists." The Donetsk regional government said seven people were killed and 39 wounded.