Workers at 12 Chilean airports whose strike paralyzed air transit, have decided end their labor action and return to work, union leaders said on Sunday.

Airport workers went on strike four days ago over pension demands, forcing airlines to cancel hundreds flights and angering crowds of Christmas holiday travelers.

Negotiators for the union called on workers to return to their jobs after the two sides agreed to resume talks.

LATAM Airlines Group, the largest in Chile and in Latin America, had said on its website that Santiago International -- a hub for air travel in South America -- reported delays on all flights.

Major airports, like those in Iquique and Antofagasta in far northern Chile were among those shuttered altogether.

Hardest hit was Easter Island, located in the Pacific some 3,500 kilometers (2,200 miles) west of the mainland, and Balmaceda, in far southern Chile. Both are accessible only by air.

The Air Force began its own flights to both locations, officials said.

Jose Perez, head of the General Directorate of Civil Aviation (DGAC) -- the group representing the 3,000 striking airport workers -- said the strike aimed to pressure the government agrees to let them join a pension plan used by the Chilean military.

The Directorate represents luggage handlers, airport security and meteorologists, but not air traffic controllers, who remained on the job.