Hecklers shouted out "murderer" and "resign" at him before the minute's silence, held across the nation.
Earlier, centre-right opposition leader Nicolas Sarkozy accused the government of failing to provide security.
Troops are to be redeployed to tourist spots as inquiries continue into the killer's possible links to jihadists.
Mr Sarkozy, a former president, called for any foreign nationals with links to radical Islam to be expelled from France.
