Protesters held at anti-Lukashenko rally in Minsk

Tens of thousands of demonstrators rallied Sunday in the Belarusian capital of Minsk to begin the fourth week of daily protests demanding that the country's authoritarian president resign.

The protests began after an Aug. 9 presidential election that handed President Alexander Lukashenko a sixth term in office but that the opposition says was rigged.

Protesters initially tried to gather at Independence Square in Minsk, but barriers and riot police blocked it off.

They then streamed down one of the capital’s main avenues, past hulking olive-green prisoner transport vehicles.

Police said 125 people were arrested, but Ales Bilyatsky of the Viasna human rights organization said more than 200 were detained.

The marchers, chanting “Freedom!” and “Resign!” eventually reached the outskirts of the presidential palace, which was blocked off by shield-bearing riot police.

There were no official figures on the crowd size, but some opposition sources claimed it exceeded 100,000.

Lukashenko says he has reached an agreement with Russian President Vladimir Putin that Russia will send in security help if asked. But Russia has appeared hesitant to get deeply involved in the Belarus unrest.

Putin and Lukashenko talked by phone on Sunday, but a Kremlin statement gave few details of the conversation, other than noting that Putin congratulated the Belarusian leader on his 66th birthday.