NEW YORK— Concerns about swine flu prompted CONCACAF to cancel the rest of its under-17 soccer championship in Mexico, the epicenter of the outbreak.

Costa Rica, Honduras, Mexico and the United States had clinched spots in the semifinals of the tournament, being played in Tijuana. But after the Mexican government announced it was closing schools nationwide, CONCACAF said today it would abandon the tournament "to safeguard the health of players, officials and fans."

Health officials say 20 deaths in Mexico are confirmed to be from swine flu, which is also suspected of causing more than 100 other deaths there.

The U.S. team, which had won all three of its group matches, was heading back to Bradenton, Fla., where the players and coaches are based.

"Our primary concern is the safety of our athletes and all of the athletes that were involved in the tournament," said Neil Buethe, spokesman for US Soccer. "If CONCACAF feels this is the best decision to ensure the safety of all the athletes, we support that."

The semifinals of the U-17 tournament were scheduled for Wednesday in Tijuana, with the championship and third-place matches on Saturday. All four teams will advance to the U-17 World Cup, which is Oct. 24-Nov. 15 in Nigeria.

CONCACAF, soccer's governing body for the North and Central American and Caribbean regions, also postponed the second leg of its Champions League finals until May 12. Cruz Azul and Atlante FC, both Mexican teams, were to play Wednesday in Cancun for the title of CONCACAF's best club team.

Atlante leads the two-game series 2-0 after winning in Mexico City last week.

CONCACAF will decide tomorrow whether to proceed with its beach championship, scheduled for Wednesday through Sunday in Puerto Vallarta.

Mexico City has been hit hardest by the swine flu epidemic, and many sports have already taken measures to help stem the outbreak. Three football games were played behind closed doors last weekend, and Cruz Azul had said it would do the same for this Saturday's game against Indios of Ciudad Juarez.

The Mexico City club played in an empty stadium Saturday at Pachuca, about 35 miles from the capital.

"We are going to wait to see how the outbreak develops," said a spokeswoman today at the Mexican Football Federation, who said she was not authorized to give her name. "There is no general policy yet, it all depends on the decision of the individual clubs."

A top baseball team moved its games this week to northern Mexico, and a weekend diving tournament — headed by leading Chinese divers — was held without any fans.

Mexico's national team, under new coach Javier Aguirre, has closed its training sessions this week at its center on the southside of the federal capital. Mexico is scheduled to host Trinidad and Tobago in a World Cup qualifying match June 10 in Mexico City. CONCACAF secretary general Chuck Blazer said it was too soon to know if that match will be rescheduled.