SANTIAGO, Chile (AP) — Hundreds of protesters defied an emergency decree and confronted confront police in Chile's capital on Monday, continuing disturbances that have left at least 11 dead and led the president to say the country is "at war."

Police used tear gas and streams of water to break up the march of students and union members on one of Santiago's main streets Monday, but demonstrators who at first dispersed later reformed elsewhere.

Meanwhile, police and soldiers guarded long lines of Chileans who lined up before supermarkets that had reopened. Many remained closed after a weekend that saw scores of stores looted or burned.

Only one of the city's six subway lines was operating because rioters had burned or damaged many of the stations, and officials said it could take weeks or months to fully restore service.

Some 2 million students were forced to stay home from classes and many people were unable to reach jobs.

Conservative President Sebastián Piñera said Sunday that the country is "at war with a powerful, relentless enemy that respects nothing or anyone and is willing to use violence and crime without any limits," though he did not say who the enemy is.

But his left-leaning rival, former President Michelle Bachelet, issued a statement calling for dialogue and urging all sides to work "toward solutions that contribute to calming the situation."

Now the U.N. high commissioner for human rights, she called for an investigation into all acts, by government or protesters," that have caused injuries and death."

The protests have shaken and surprised a nation noted for economic stability over the past decades, which has seen steadily declining poverty despite persistent high rates of inequality.

They were triggered by a relatively minor increase in subway fares of less than 4%, but analysts said they were fed by frustration over a long-building sense that many Chileans were not sharing in the nation's advances.

"People went out to protest because they feel the government cares more about the wealthy and that social programs help the very poor, but the rest of the population is left to care for themselves," said Patricio Navia, a professor at the Center for Latin American and Caribbean Studies at New York University.

"They are not poor enough to get government subsidies nor rich enough to get government tax credits. They revolted to make their voice heard," he added.

Otherwise peaceful Chilean protests are also often used as springboards for more violent action by smaller, hardline factions that want to overturn the social system.