Prime Minister Petr Necas of the Czech Republic said Thursday that he had no intention of resigning after the authorities from an organized crime unit raided government offices in Prague and arrested several officials, including one of his senior aides.

Several hundred officers took part in the nationwide raid that included the Defense Ministry, government headquarters and City Hall in Prague, the capital, the Czech news media reported. The reports said the police had also searched safe deposit boxes at a branch of Komercni bank in Prague and conducted a sweep of the offices of influential lobbyists.

Interior Minister Jan Kubice told Parliament on Thursday that Mr. Necas had been visited by the head of the organized crime unit and two state attorneys. He said the visit was “in connection with a step in the criminal proceedings,” but did not elaborate.

According to the online version of Mlada fronta DNES, a leading Czech newspaper, those arrested included Jana Nagyova, the prime minister’s chief of staff and a close and influential aide. Czech news media reports said she had come under scrutiny in the past for receiving large bonuses from the state.