A Belarusian court jailed a drummer for six years on Thursday after his band played at mass protests in the wake of disputed presidential elections last year, a rights group said.

Belarus was for months gripped by weekly demonstrations demanding the resignation of strongman Alexander Lukashenko, who claimed a landslide victory in the August vote that his opponents said was rigged.

The 66-year-old has ruled Belarus with an iron fist for over two decades and moved quickly to stamp out protests following the vote.

Alexei Sanchuk, 30, was arrested in the capital Minsk in November, along with several other members of a marching percussion band that were often seen at protests.

They were sentenced to 15 days in jail for taking part in unauthorised protests, but Sanchuk was held following the sentence and slapped with several criminal charges.

On Thursday, a court in Minsk found him guilty of organising and participating in protests and sentenced him to six years in a penal colony, the Viasna rights group said.

He was accused of blocking traffic, waving a red-and-white flag -- a symbol of the Belarus protest movement -- and encouraging protesters to clap their hands, among other acts that allegedly breached public order.

Viasna said the musician was reported to have been beaten after his arrest and was forced to appear in a video confession that was shown on state-run television.

Sanchuk has a wife and an eight-year-old daughter.

While the historic protests that left at least four people dead have by now subsided, journalists and activists continue receiving prison terms in the aftermath.