* Seven protesters, two police officers wounded
* Deputies, ministers, journalists blocked in parliament
* President appeals to keep protests peaceful (Adds president's comment)
Hundreds of protesters blocked the doors of Bulgaria's parliament on Tuesday, scuffling with police officers and preventing lawmakers from leaving the building.
Shouting "Mafia!" and "Resign!", opponents of the Socialist-led government threw plastic bottles and other objects at a heavily guarded bus that tried to get deputies out of the parliament where they had been discussing budget measures.
Thousands of Bulgarians have been protesting almost daily in Sofia since last month following a government decision to name a powerful media magnate as security chief, which many see as an example of private interests controlling state institutions.
The government's withdrawal of the appointment failed to quell public discontent in the European Union's poorest country, which also is one of the bloc's most corrupt.
Seven protesters with light head injuries were treated at Sofia's emergency hospitals, the national radio said. Two police officers were also wounded.
After several attempts to leave the area around the parliament, the bus returned the deputies to the building, national radio reported.
Scuffles with police - who wore helmets and carried shields and batons - ended, but protesters were still blocking parliament, with more than 100 deputies, ministers and journalists inside, late into the night.
President Rosen Plevneliev appealed to protesters and police to keep the demonstrations peaceful as they were in the past 40 days, and to avoid provocations.
"I appeal to the protesters to keep the protest the way it was and the way it impressed all Europe - peaceful, civilised and aimed at achieving the values of a democratic society," Plevneliev said in a statement.
Opposition centre-right GERB party urged Prime Minister Plamen Oresharski to resign immediately and called on the president to hold an emergency meeting of the national security council.
Earlier on Tuesday, the European Union's justice commissioner Viviane Reding said she sympathised with the protesters who rallied against corruption, and urged the government to reform its judicial system.