More than 150 policemen in riot gear broke into a prominent London mosque with battering rams in a dramatic 2 A.M. raid this week, as part of the investigation into last weeks discovery of the poison ricin in the apartment of Algerian immigrants. The police arrested seven people at the mosque and confiscated a stash of passports, ID cards, and credit cards. The Finley Park mosque is run by Abu Hamza al-Masri, a radical cleric who lost both hands and an eye fighting the Soviets in Afghanistan, and who supports a violent holy war against the West. Zacarias Moussaoui, the 20th hijacker, and Richard Reid, the shoe bomber, both worshiped there. Masri condemned the raid as a desecration of the mosque, but Scotland Yard officials said the police wore covers over their shoes and entered only the offices, not the sacred areas.