SOFIA, Feb 27 (Reuters) - The Bulgarian Football Union (BFU) has banned two referees for life and suspended three others for a year for making mistakes in premier league matches.Momchil Vraikov and Dimitar Dimitrov have been given life bans while Petar Stoyanov, Ivaylo Bozev and Dimo Radev have been suspended for one year, the BFU said ahead of the start of the second half of the domestic championship this weekend. Vraikov and Dimitrov had already been taken off the list of officials by the BFU's referee commission for an unspecified period but now their bans have been made permanent. 'They (Vraikov and Dimitrov) have committed a lot of errors and there were complaints about them from most of the clubs in the premier league,' said Borislav Alexandrov, chairman of the referee commission. Referee suspensions are not uncommon in Bulgaria, with four officials receiving bans in the first half of the season. 'It's a severe sanction but they've made too many mistakes and it was an unanimous decision to ban Vraikov and Dimitrov for life,' said BFU's president Borislav Mihailov. The BFU's decision came only a few weeks after several of the Balkan country's leading teams, including champions Levski Sofia, expressed their unhappiness over the standard of Bulgarian referees. Levski, CSKA Sofia and some other clubs have already considered asking foreign officials to take charge of matches. The Bulgarian championship resumes on March 3 after its mid-season break. Levski Sofia top the standings with 39 points from 15 matches, two points ahead of CSKA.