BELGRADE, Serbia (AP) — Several hundred people have gathered at an opposition protest demanding that an upcoming local election in the Serbian capital of Belgrade be free and fair.

Opposition leaders have alleged that the ruling parties have been beefing up voters' lists ahead of the ballot expected next spring. The authorities have denied this.

The Belgrade race is viewed as a test of President Aleksandar Vucic's rule. Vucic swept the presidential elections earlier this year and his right-leaning coalition controls the government, but opposition parties are hoping to undermine his power in Belgrade.

Opposition leaders have accused Vucic of stifling democratic freedoms, exerting pressure on the media and threating opponents.

Protesters on Friday put forward a set of demands, including equal treatment in the media and international observers at the Belgrade vote.