Chile has extended a state of emergency to cities in the country's north and south amid an "escalation of violence and vandalism."
Officials said five people died when a garment factory was torched in a suburb north of Santiago, bringing the death toll in a wave of unrest in Chile to seven.
"We are at war against a powerful enemy, who is willing to use violence without any limits," President Sebastian Pinera said in a late-night televised statement at army headquarters in Santiago.
"I call on all my compatriots to unite in this battle against violence and delinquency."
Protests led by students began two weeks ago over fare hikes on public transport.

Nepal to rebuild early-warning system on China border after deadly flood, sources say
Kuwait air defences deal with Iranian missile, drone attacks
Spain's PM Sanchez says no evidence Morocco orchestrated Ceuta border surge
Two Palestinian teens killed in West Bank raid by Israeli settlers, army
Latest Indonesian free meal poisoning outbreaks affect 800, lawmaker says
