Georgia's opposition said dozens of supporters had been detained overnight ahead of mass rallies against President Mikheil Saakashvili on Thursday by critics emboldened by last year's disastrous with Russia.
An Interior Ministry spokesman denied the allegation.
Opposition leaders, their ranks swollen by defectors, are predicting turnout of 150,000 on Thursday, and say protests will continue daily until Saakashvili, 41, resigns and calls elections.
The opposition accuses Saakashvili of exercising an authoritarian streak to stifle the democratic reforms that were promised in the 2003 Rose Revolution that swept him to power in the former Soviet republic.
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War in August, when Russia crushed a Georgian assault on the breakaway South Ossetia region and sent tanks to within 40 km (25 miles) of Tbilisi, emboldened critics who say the president has made too many mistakes to stay in power until 2013.
ACTIVISTS HELD?
The opposition Democratic Movement-United Georgia party of former Saakashvili ally Nino Burjanadze said around 60 activists had been detained in the town of Rustavi, southeast of Tbilisi.
"They were planning to come to Tbilisi today to attend the rally," party spokeswoman Khatuna Ivanishvili said.
