KIEV, Ukraine (AP) _ The speaker of Ukraine's parliament huddled under umbrellas as eggs rained down and smoke bombs filled the chamber with an acrid cloud. Then the lawmakers attacked each other, punching and brawling in the aisles.

The chaos erupted Tuesday as parliament approved a treaty allowing Russia to extend the lease on a naval base in a Ukrainian port on the Black Sea until 2042 _ a move bitterly opposed by pro-Western lawmakers. Ukraine would get cheap natural gas from Russia in exchange.

Russia's influence in Ukraine has surged since the February election victory of pro-Kremlin President Viktor Yanukovych, infuriating Ukrainians who resent Moscow's influence and inflaming the violent passions that plague the politics of the former Soviet republic.

The controversy over the home port for the Russian Black Sea Fleet has been one of the most emotionally charged consequences of the breakup of the Soviet Union. After the Soviet collapse, Russia found one of its major fleets based in a foreign country's port _ Sevastopol, on the Crimean peninsula that extends from mainland Ukraine into the Black Sea, about 200 miles from the nearest Russian territory.

Ukrainian nationalists who resented Moscow's long dominance of their land regarded the Russian fleet's presence as tantamount to military occupation. Former President Viktor Yushchenko, who tilted toward the West, had vowed that the fleet's lease of the port would not be renewed when it expired in 2017.

Yanukovych and Russian President Dmitry Medvedev agreed last week that the lease would be extended for 25 years past that expiration. Russian Prime Minister Vladimir Putin discussed the matter Monday in Kiev with Yanukovych.

As parliament speaker Volodymyr Lytvyn opened Tuesday's legislative session, opposition members threw eggs at him, forcing him to preside behind two black umbrellas held by aides.

Opposition lawmakers draped a huge Ukrainian flag over their seats, a signal they would abstain from voting.

Lytvyn defiantly forged ahead amid the falling eggs, calling lawmakers to the stand to make their case on the Black Sea Fleet deal.

About seven minutes into the session, a smoke bomb went off underneath the draped flag and another was hurled from the back of the gallery. The chamber filled with an acrid cloud as smoke alarms went off _ unprecedented scenes in the parliament.

The lawmakers' bickering deteriorated into members throwing punches and grappling during the nationally televised session. The opposition bloc Our Ukraine-People's Self-Defense said one of its lawmakers was hospitalized with a concussion after fighting with Yanukovych's party.

Outside, riot police kept back crowds of opposition supporters trying to get closer to the parliament building, which was surrounded by Yanukovych supporters. Passions among the thousands of protesters became heated after the vote, but they quickly simmered down. No arrests were reported.

The base extension passed with 236 votes in the 450-member parliament.