Russia staged a huge May Day parade on Moscow's Red Square for the first time since the Soviet era on Thursday, with workers holding banners proclaiming support for President Vladimir Putin after the seizure of territory from Ukraine.

Thousands of trade unionists marched with Russian flags and those of Putin's ruling United Russia party onto the giant square, beneath the Kremlin walls and past the red granite mausoleum of Soviet founder Vladimir Lenin.

Many banners displayed traditional slogans for the annual workers' holiday, such as "Peace, labor, May." Others were more directly political, alluding to the crisis in neighboring Ukraine, where Russia's annexation of Crimea in March precipitated the biggest confrontation with the West since the Cold War.