Nationwide rallies are being organized Sunday afternoon against what some see as the artificially inflated prices of fuels.

This is the sixth protest to be held in cities and towns across the country, organized by the civil association "Sila" (Strenght), uniting Bulgarians against the monopoly on fuels.

13 towns and cities are to take part by staging marches and blockades of key roads, according to the organizers.

The first protest rallies happened in April. The Sunday ones are beginning around 5 pm.

The protests come all while Bulgaria is shaken by the news that Neftochim, the only oil refinery in the country, controlled by Russia's giant Lukoil, had started on Wednesday to reduce crude processing to effectively stop production after the customs office revoked its licenses.

Vanyo Tanov, Director of the Customs Agency, has explained that the refinery cannot operate without the required electronic measuring devices Lukoil failed to install in its storage facilities, and can deal only with the fuels already outside the plant.

Valentin Zlatev, CEO of Lukoil Bulgaria, has often been described as "the country's back seat ruler" and "the oil oligarch, who pulls the strings of the government".

He is suspected of being the man behind Bulgaria's Prime Minister Boyko Borisov.

Zlatev has strongly denied the allegations.