French prosecutors have opened an investigation into a suspected attempted murder after an incendiary bottle hit a gendarme during protests in Paris and set his uniform on fire. The incident happened in the east of the French capital during Saturday anti-government demonstrations. The gendarme was burned while his gear and trousers caught fire, and he was helped by a man from the crowd before another officer pushed that person away. Police said masked attackers struck security forces after the march ended, using paving stones, bottles and incendiary devices. Prosecutors said explosive devices were thrown at around 15 gendarmes and other police. Authorities launched the investigation Sunday and are probing the attack as a suspected attempt to murder public officials. The accused individuals have not been detained so far. The injured gendarme suffered second-degree burns. The interior minister Laurent Nuñez called it an attempted murder and condemned the violence. Marine Le Pen also criticized the attack. During the protests and related Halloween festivities, police detained 779 people. A total of 159 officers and members of security forces were reported injured. Organizers said the protests drew nearly half a million people, while authorities cited 320,000 attendees. The protest movement is preparing further school blockades and November demonstrations.