SANTIAGO (REUTERS) - At least three people died in supermarket arson attacks in Chile's capital Santiago, and soldiers shot two people during an operation to detain looters, authorities said, as protests entered their second week and intensified after a state of emergency was announced.

There was transport deadlock in the city and chaos at the international airport, where flights into and out of Santiago were suspended or cancelled as crew members and airport staff were unable to get to work, the city's governor said.

Santiago and other Chilean cities have been engulfed by several days of riots as protests over an increase in public transport costs prompted President Sebastian Pinera to reverse the move and declare a state of emergency.

Santiago governor Karla Rubilar said on Sunday (Oct 20) that three people died a day earlier after a supermarket in the San Bernardo district to the south of the city was set on fire by demonstrators.

Chile's Interior Minister Andres Chadwick said later that two people died in the supermarket, while one was in hospital with serious injuries.

Prosecutor Xavier Armendariz said a fourth person died in another fire at a supermarket in Matucana, in the center of Santiago.

By mid-afternoon on Sunday, prosecutors said 1,462 people had been charged in connection with that day's protests, 614 of them in Santiago. That followed 179 arrests in Santiago on Saturday.

Chadwick said more than 240 were taken into custody for violating a 10 p.m. to 7 a.m. curfew for the capital that was announced on Saturday evening, the first since the end of the Augusto Pinochet dictatorship between 1973 and 1990.

The interior minister said he could not rule out extending the state of emergency declared for Santiago to Valparaiso, Bio Bio, Coquimbo and O'Higgins regions.

The military authorities mandated by Pinera with reestablishing order in Santiago said on Sunday they had shot and wounded two people before dawn in the impoverished La Pintana neighbourhood during an attempt to detain people who ransacked a supermarket during the curfew.

One of the injured was a passenger in a car that drove at a military convoy and failed to heed warning shots, while the other was a bystander, the military said in a statement.

Walmart Chile confirmed said it had closed stores across the country after six were torched and 111 looted.

Flights operated by Chilean airlines Latam and Sky Airline were suspended or delayed on Sunday morning after the curfew, a public transport shutdown and ongoing riots left flight crews struggling to get to work, Rubilar said.

Crowds of passengers were left stranded at the airport.

Latam Chile said on Twitter that, due to the public order situation, flights into and out of the capital were affected.

"We will continue to adjust our itineraries of flights into and out of Santiago on Oct 20 and 21," the airline said, adding passengers should check details before going to the airport.