At least seven people were killed amid violent clashes and arson attacks over the weekend in Chile, the country's Interior Minister said.
Protests led by students began two weeks ago over fare hikes on public transport.
The government will extend a state of emergency to cities in its north and south, President Sebastian Pinera said late on Sunday.
"We are at war against a powerful enemy, who is willing to use violence without any limits," Pinera said in a late-night televised statement at army headquarters in Santiago.
He confirmed the state of emergency he declared for Santiago on Saturday night, which brought the military onto the streets, would be extended to the north and south of the capital.
Pinera said Santiago's metro and bus system would operate a partial service on Monday, along with hospitals and some schools
"Tomorrow we will have a difficult day," he said. "We are very aware that (the perpetrators of riots) have a degree of organization, logistics, typical of a criminal organization," he said.
Interior Minister Andres Chadwick told news conference in Santiago earlier on Sunday night that the decision to extend the emergency measure came amid an "escalation of violence and vandalism."
He cited 70 "serious incidents of violence" on Sunday, including the looting of 40 supermarkets and other businesses.
Chadwick said military and police numbers were at 10,500 in Santiago and would be reinforced where necessary.
Prosecutors said 1,462 people had been charged by mid-afternoon on Sunday in connection with that day's protests, 614 of them in Santiago, That followed 179 arrests in Santiago on Saturday.
The military authorities mandated by Pinera with reestablishing order in Santiago declared on Sunday another night-time curfew in the capital as the government struggled to contain violence.
However, several large demonstrations continued past the mandated curfew hour, witnesses and Chilean media reported.