Flight cancellations and hours-long delays continued to haunt holiday travelers at airports across Brazil on Saturday despite an emergency intervention by the nation's air force.

President Luiz Inacio Lula da Silva on Friday called in the Brazilian air force to help transport airline passengers on an emergency basis, but it was not enough to ease the situation.

Overbooked flights and delays of up to 24 hours caused protests and anger among travelers stuck in airports. An upset woman was detained at Rio de Janeiro's international airport after tossing a computer toward airline employees, breaking one worker's arm.

In Sao Paulo, passengers were lining up for check-in along the sidewalks outside the metropolitan airport of Congonhas — the country's busiest.

"We had airlines overbooking, they sold tickets they could not have sold," Silva said. "The air force is helping and we can expect that by (Sunday) things will get better and passengers will be able to fly with tranquility."

Air force planes began transporting stranded passengers late Friday, but due to the low passenger capacity of the eight jets — two Boeing 707s, two Boeing 737s and four Embraer EMB-145s — only 760 people were expected to be transported by the end of Saturday.

Tam Linhas Aereas SA, Brazil's No. 1 carrier, had the worst problems of all. Six of its aircraft were unable to take off Wednesday because of maintenance problems, causing a "snowball" effect of canceled and delayed flights.

All of Tam's flights were delayed at the Brasilia and Rio de Janeiro airports on Saturday.

The company said in a statement it was doing everything possible "to bring normality back to Brazilian airports."

The National Agency of Civil Aviation, ANAC, ordered Tam to halt ticket sales Friday as "predicted improvements in the treatment of passengers did not occur, with the persistence of delays."

ANAC president Milton Zuanazzi said the situation was expected to be solved by Saturday evening.

"These problems won't occur again, they cannot occur on the eve of a holiday," Zuanazzi told the GloboNews TV.

Nearly half of the 675 flights in 67 Brazilian airports were delayed by at least an hour on Saturday morning, ANAC said.

The latest airport woes started on Tuesday after the Congonhas airport had to be shut down due to bad weather.

Brazil's airports have been plagued by problems since a midair collision between a Gol airlines Boeing 737 and an Embraer Legacy 600 executive jet killed 154 passengers on Sep. 29 in the country's worst air disaster.

After the crash, air traffic controllers began following regulations to the letter in a "work-to-rule" protest to demand better pay and working conditions.

On Dec. 5, authorities suspended takeoffs from three major airports for several hours after an air control system failed, prompting an unprecedented wave of flight cancellations.