A guard of honor march to the eternal flame on Nakhimov Square on the memorial of the heroic defense of Sevastopol (1941-1942) as Crimeans celebrate the first anniversary of the referendum on March 16, 2014 in Sevastopol, Crimea. Today marks the first anniversary of the referendum which resulted in the annexation of the territory by Russia.
Is march used as a verb here? If so, then I must presume that a guard of honor is a plural noun, but it does not sound plural to me at all. Another way to look at this sentence, though, is treat guard of honor as an adjective describing march, but that can't be right either since structurally that part must be the main clause of this rather long sentence and would require a verb which would be missing. Which interpretation do you think is the correct one or am I completely wrong about all this?