Martelly, his prime minister, Laurent Lamothe, and the first lady attended a church ceremony in the northern city of Cap-Haitien, the site of another, smaller protest Monday, a national holiday that commemorates Haiti's final battle before it secured independence from France in 1804.
In a speech that followed at a historic site where the fight apparently took place, Martelly appealed for unity. "If we didn't put our heads together, we wouldn't have had the Battle of Vertieres," he said. "If we didn't have our heads together, we wouldn't have a Haitian state."
The U.N. peacekeeping mission in Haiti on Saturday urged Martelly and opposition parties to sort out their differences in a peaceful manner. The world body also dispatched armed troops for the demonstration to join riot police with shields and helmets.
The mounting tension between Martelly and his opponents stems in part from the government's failure to hold legislative and local elections that are two years overdue. The U.N., U.S. and others have been overly supportive of the Martelly administration but relations seemed to be straining in recent months because of the delayed vote. The election was supposed to have been held before year's end, but it most likely won't happen until next year.
"The international community should take notes," said Moise Jean-Charles, a senator and vocal critic of the government. "The people are rising for a change. Martelly and Lamothe aren't doing anything for the country but stealing money."