Gyorgy Budahazy, a right-wing extremist who terrorized politicians in Hungary over a two-year period with bomb attacks, was sentenced to 13 years' imprisonment in a tumultuous court hearing on Monday.
The Budapest court ruled that Budahazy was behind a number of bombings targeting the homes of government politicians from 2007 to 2009. None was fatal but the blasts caused some injuries.
Fourteen other co-defendants received custodial sentences ranging from five to 12 years for their involvement in the violence.
A commotion broke out in court after the state prosecutor announced his decision to appeal, with dozens of Budahazy's supporters having to be forcibly removed by the police.
Members of Budahazy's radical group also battered a television presenter, who had to receive hospital treatment as a result.
Budahazy denied the charges against him, rejecting evidence provided by witness accounts and wire-tapping.
The rightist gang leader was a prominent figure in the Budapest rioting of 2006, which broke out after the socialist premier at the time, Ferenc Gyurcsany, admitted that he lied in order to win an election and that his government had failed to come up with any real policies.