MONTREAL — Ceremonies marking Israel's national day took on many forms in Canada, from a party-like demonstration in Montreal that drew hundreds of supporters of the Jewish state to a flag-raising in Ottawa held in secret because of undisclosed threats. Israel's flag was flying on Tuesday morning at Ottawa City Hall to commemorate 76 years since the state of Israel's 1948 creation, but there was no public ceremony for the occasion. Instead, the city said, the Jewish Federation of Ottawa organized a private event, but officials refused to say when or where it was happening. City officials said they had...