KYIV, Ukraine (AP) — The Belarusian human rights group Viasna says that more than 140 people were arrested and many of them beaten by police during protests calling for the country’s authoritarian president to resign.

The demonstrations that attracted thousands were the 16th consecutive Sunday of large protests against President Alexander Lukashenko.

There have been near-daily protests since early August, but those on Sundays have been the largest.

Protests have gripped Belarus since the Aug. 9 presidential election that official results say gave Lukashenko a sixth term in office, but that the opposition and some poll workers say were manipulated.

Throughout the protest wave, more than 19,000 people have been detained and thousands of them beaten, human rights advocates say.

The protesters on Sunday tried to dilute detentions and police dispersals by initially gathering in various parts of the capital Minsk, but were met by police when they tried to converge on the center. Police used stun grenades to turn them back and began widescale detentions.