At least 40 chartered buses full of people from all over Bulgaria arrived in Sofia early on Friday to offer a helping hand to the embattled coalition government, as a fresh anti-graft rally gathered in the capital.

The buses arrived from the towns of Kardzhali, Stara Zagora, Gotse Delchev, Sliven and Plovdiv, among others, according to reporters.

"I don't know," a young counter-protester from Stara Zagora told the local Channel 3 upon asked why he arrived in Sofia.

"Are we backing the government or protesting against it?" another "government supporter" was heard asking somebody on the phone.

Both the government supporters and the anti-government protesters have now gathered at the Alexander Nevsky square.

Police are making sure that no clashes erupt between the two groups. However, brief violent encounters erupted after protesters tried to break the police cordone, set up to keep the two rallies apart.

The Bulgarian Parliament is holding a special plenary sitting Friday morning to discuss and vote on Bulgaria President Rosen Plevneliev's veto on a controversial recent budget update.

Since June 14, Bulgarian capital Sofia has been gripped by strong anti-corruption rallies against the Socialist-led new government of PM Plamen Oresharski, which however have abated during the holiday month of August.

Anti-government protesters are also largely against the budget revision, which, if implemented, would see the government taking a BGN 1 B loan to be largely used for paying arrears to businesses and increased social benefits.

President Plevneliev has motivated his veto by what he has called the lack of transparency and the excessive amount of discretionary spending in the revision.