Two U.S. citizens and one Russian were among 20 people detained at protests in Tbilisi while Georgian lawmakers were debating a "foreign agents" bill that has sparked a political crisis, the interior ministry said on Monday, Reuters reported.

The protesters were among several thousand opponents of the bill who heeded a call from Georgia's opposition to stage an all-night protest outside parliament with the intention of preventing lawmakers from entering the building on Monday.

However, lawmakers were able to get into the parliament building where the judiciary committee - boycotted by opposition parties - formally approved the legislation in a one-minute session. The full assembly is expected to debate and approve the bill on its third and final reading as early as Tuesday.

The U.S. embassy and Russia's diplomatic representatives in Georgia did not immediately reply to emailed requests for comment on their detained citizens. Russia does not currently have an embassy in Georgia, due to the countries' dispute over two Moscow-backed breakaway regions.

The Georgian interior ministry wrote on Facebook that one of the U.S. nationals was born in 1995 but offered no further details.

Georgian media, citing witnesses, reported that police had pushed protesters away from the service entrances of the parliament building early on Monday, leading to some scuffles.

Georgian Prime Minister Irakli Kobakhidze has vowed to press ahead with the bill despite it having caused some of the largest protests seen in the South Caucasus nation since it won independence from Moscow in 1991.

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