Tens of thousands of Bulgarians rallied across the country on Sunday, in the latest sign that the government's resignation last month failed to calm public anger about poverty and corruption.
In the capital Sofia metal fences and a heavy police presence prevented protesters from reaching an official flag-raising ceremony for national liberation day commemorating the end of Ottoman occupation in 1878.
But around 7,000 demonstrators, according to AFP estimates, blocked traffic on several key boulevards for hours, waving white-green-and-red Bulgarian flags and shouting "Mafia!"
Local media said that over 20,000 gathered in the Black Sea city of Varna where the initial protests against high electricity bills started last month, calling for the resignation of mayor Kiril Yordanov.
Smaller protests were held in about a dozen other cities, gathering between several hundred and several thousand people, reports said.
In Sofia, protesters carried slogans that read "Anarchy against organised crime and the monopolies!", "The mobsters in jail!" and "People against the mafia."
Lawyer Ivan Hristov, who raised a "Power to the people" slogan as the rally passed by the parliament buildings, told AFP that protesters wanted more say in how the country was run.
"We will rally outside parliament on Wednesday to demand changes to the elections code to give civil groups the same rights as those enjoyed by political parties," he said.
A major rally of supporters of the ultra-nationalist Ataka party was also expected in Sofia later on Sunday.
Bulgaria has been rocked for three weeks by sometimes violent demonstrations over high electricity prices, deepening poverty, cronyism and corruption in the European Union's poorest member state.
The rallies forced the surprise resignation on February 20 of tough-guy Prime Minister Boyko Borisov's government five months before his term was due to expire, clearing the way for early elections on May 12.
Political analysts say the election could return a highly fragmented new parliament that might make the formation of a new government extremely difficult.