Surging crowds broke through police lines at a square in Georgia where U.S. President George W. Bush was expected to speak on Tuesday, raising security concerns ahead of the address.
Thousands of people poured on to Freedom Square from surrounding streets after tiring of elaborate security procedures. Rustavi-2 television showed pictures of huge crowds on the square, with barricades toppled and smashed to the ground.
Authorities in Georgia were not immediately available for comment.
Bush, who held a news conference immediately after the surge, was not at the square as the crowds poured in.
U.S.-educated president, Mikhail Saakashvili told reporters that as many as 150,000 people had gathered on the square.
Bush's landmark visit has prompted great enthusiasm in Georgia. Georgians hope the trip will increase pressure on Russia to withdraw two Soviet-era-holdover bases it maintains on Georgian territory and to stop giving support to two separatist regions.
Georgia has an uneasy relationship with Russia, its giant neighbor and main energy supplier, and Bush's visit is getting a near-universal welcome.