The Tel Aviv Magistrate's Court on Monday extended the remand of Nissim Alperon, brother of the slain mobster Ya'acov Alperon, and three other suspects by seven days, following Alperon's dramatic arrest in a Ramat Gan cafe on Sunday evening. Tel Aviv Police detectives swooped on the cafe and arrested Alperon and 18 other men, recovering a gun from a moped belonging to one of the suspects. Police remain very concerned about possible attempts by surviving Alperon family members to violently avenge Yaacov Alperon's car bomb assassination last month. Alperon and three suspects have been charged with conspiracy to commit a crime and possession of a gun. Since the arrests Sunday, police have been cagey over what had been going on at the meeting they raided. A Tel Aviv police source told The Jerusalem Post said he did not know whether Alperon and the suspects were plotting a revenge attack. During Monday's remand hearing, Judge Tzion Kapah said his decision "would not deal with the content of the conspiracy [to commit a crime] in order to avoid inflaming passions. It is possible to, God forbid, cause a needless additional spilling of blood." Police heavily guarded the Tel Aviv courtroom in which Alperon, who has grown a beard during the mourning period for his brother, and three other suspects appeared for the remand hearing. Alperon displayed hostility towards the press photographers attempting to take his picture, telling them to photograph his backside. Lawyers for the suspects said police had no basis to launch the raid, adding that Alperon had arrived in the area with his young children for a meal. They claimed he had no access to the gun found in the moped. But Kapah rejected their arguments, saying the gun was a marginal point in a far larger case. Intelligence and solid investigation findings have been made available to the court, Kapah said, adding that he was extending the remand due to concerns that releasing Alperon would subvert the police investigation. Last month, underworld boss and explosives expert Amir Mulner, a prime suspect in the Alperon hit, was arrested during a police raid on a Ramat Gan apartment. He and several other suspects in the apartment were charged with conspiracy to commit a crime and possession of a gun with a silencer. Police have not officially linked the arrest to Alperon's assassination at this stage. Police were desperate to keep Mulner in custody, and launched a determined court battle to reverse an earlier decision by a Tel Aviv Magistrate to release him to house arrest. The efforts succeeded after police convinced the Tel Aviv District Court to keep Mulner in custody last week.