Tens of thousands of protesters took part in a protest in the Macedonian capital Skopje, demanding the resignation of Prime Minister Nikola Gruevski.
The rally follows the release of tapes which seem to record ministers plotting vote rigging and the cover-up of a murder.
Crowds gathered outside the prime minister's office in the city, holding aloft both Macedonian and Albanian flags in a show of unity.
The government accuses the opposition, which released the tapes, of attempting to destabilise the country.
The protests follow violent clashes between police and ethnic Albanian militants in the northern town of Kumanovo last weekend, in which eight officers and 14 rebels were killed.
The unrest was the worst the country has witnessed since the 2001 conflict between the government and ethnic Albanian rebels.
Opposition leader Zoran Zaev said that protesters would remain outside government buildings until Gruevski and his government stepped down.
"The protest will continue. Some 4,600 activists, mostly young people, have said 'we'll stay regardless of whether you will or not'," he told the NOVA online TV channel.
Zaev's Social Democratic Union of Macedonia (SDSM) boycotted April elections alleging electoral fraud by the ruling VMRO-DPMNE party.
Thirty alleged gunmen have been charged with terror offences following the attack.
The opposition said that the timing of last weekend's attack was suspicious, and alleges it was manipulated in order to detract from the growing unpopularity of the government.
The government claims the tapes were edited to as to distort comments made, and deny the allegations made against it.
Two ministers and an intelligence chief have resigned in the wake of the release of the tapes.