Former Congolese vice-president Jean-Pierre Bemba's lawyer and a member of his party have been arrested on suspicion of tampering with witnesses in the ex-warlord's war crimes trial in The Hague, party officials said Sunday. The chairman of Bemba's opposition party the Movement for the Liberation of Congo (MLC) said International Criminal Court warrants were carried out against lawmaker Fidele Babala Wandu in Kinshasa and lawyer Aime Kilolo at Brussels airport. The ICC confirmed a total of four arrests had been made, including Babala Wandu and Kilolo. MLC spokesman Germain Kambinga told Agence France Presse Babala Wandu was arrested at his home overnight Saturday to Sunday by security forces holding the ICC warrants. He was being held in the prosecutor's office in Kinshasa. "We did not know about this warrant. We were all surprised, we are in shock," Kambinga said. Following news of the arrests, members of the MLC met with the president of the National Assembly, Aubin Minaku, to discuss the "regrettable incident," Kambinga said. The 57-year-old Babala Wandu was Bemba's private secretary when he was DR Congo's vice-president from 2003 to 2006. Bemba's rebel army is accused of atrocities in the Central African Republic and he has been detained by the ICC since 2008, charged with three war crimes counts and two of crimes against humanity for murder, rape and pillaging.