BEIRUT, July 13 (Reuters) - Police fired tear gas to try to disperse relatives of victims of last year"s Beirut port blast protesting outside the home of the caretaker interior minister on Tuesday over his refusal to let the lead investigator question Lebanon"s security chief. Nearly a year after the Aug. 4 explosion, which killed more than 200 people, wounded thousands and devastated swathes of the capital, many Lebanese are furious that no senior officials have been held to account. Judge Tarek Bitar had asked to question Major General Abbas Ibrahim, head of the General Security agency, alongside other top officials including three lawmakers and the caretaker prime minister Hassan Diab, but was turned down. read more Over 100 people gathered around Fahmy"s home on Tuesday, calling him a "terrorist", according to a Reuters witness, before pushing their way into the entrance of the building, some of them writing on the walls, "Fahmy is a criminal". "The Lebanese people have come to support us, where are you, hero?" a demonstrators yelled mockingly through a megaphone. Scuffles ensued with police, who repelled protesters from the building entrance after firing tear gas, but the crowd refused to leave the area and tensions rose as more riot police arrived at the scene, witnesses said. Parliament has yet to decide whether to lift the immunity of former finance minister Ali Hassan Khalil, former public works minister Ghazi Zeaiter and former interior minister Nohad Machnouk in connection with the port inquiry, after adjourning proceedings on Friday to seek more information from the judge. Bitar became the lead investigator into the blast after his predecessor, Judge Fadi Sawan, was removed in February following requests from two former ministers whom he had charged with negligence over the blast.