MINSK (REUTERS) - Hundreds of students boycotted the start of the school year in Belarus on Tuesday (Sept 1), answering a call from exiled opposition figure Svetlana Tikhanovskaya to demand new elections and keep the pressure on President Alexander Lukashenko to resign.

Mr Lukashenko is battling a wave of protests and strikes since claiming victory in an election last month that his opponents say was rigged. He denies electoral fraud and shows no sign of backing down despite the threat of Western sanctions.

Many state-run schools were used as polling stations and teachers helped count the ballots in the Aug 9 election, which the election commission said Mr Lukashenko won with an 80 per cent vote share to secure a sixth term.

Students waving opposition flags marched in the street and collected signatures outside several colleges in Minsk calling for Mr Lukashenko to step down, an eyewitness said.

Videos on social media showed some students being detained.

Ms Tikhanovskaya's team said the boycott was necessary to "show that young people cannot stay away from the events taking place in Belarus".

Mr Lukashenko sought to draw a line under three weeks of protests against his rule as he visited a vocational training college in the city of Baranovichi in south-western Belarus.

"The President emphasised that the eventful summer is over," the official Belta news agency in a press release.

"It is time to channel energy into the creative direction," it quoted the President as saying.

Mr Lukashenko has described the protesters as "rats" that are backed from abroad.

On Monday, a third member of an opposition council set up by Ms Tikhanovskaya to negotiate a transfer of power was detained.

Lithuania, Latvia and Estonia have imposed travel bans on Mr Lukashenko and 29 other Belarusian officials.

The European Union has been working on its own list of individuals to target with similar sanctions, but is expected to exclude Mr Lukashenko. Western countries have mostly been cautious, wary of provoking an intervention from Russia.

Mr Lukashenko has threatened to cut off European transit routes across his country in retaliation against any sanctions.