MOSCOW — With relations between Russia and Georgia heading toward their lowest ebb since a brief war in 2008, thousands of protesters gathered in the Georgian capital of Tbilisi for a third night on Saturday, waving banners and shouting slogans against Russian meddling.

The latest opposition-led demonstrations, fired by fury at both Moscow and the Georgian government, followed a decision late Friday by President Vladimir V. Putin of Russia to cancel all flights from Russia to Georgia starting on July 8. It was a move clearly designed to hit Georgia’s booming tourist industry.

The daily protests outside Georgia’s Parliament, organized by opposition activists and students, began on Thursday, when a large crowd of mostly young people, angry that a Russian legislator had been allowed to speak inside the building, violently clashed with police officers. At least 240 people were injured, many hit by rubber bullets fired by security forces, who also used tear gas.

The violence, which state-controlled Russian media outlets presented as a frenzy of Russophobia orchestrated by mysterious English speakers with American accents, has sent relations between the countries into a tailspin.