Sao Paulo are searching for a venue for their match with Mexicans Guadalajara [EPA]

Copa Libertadores ties involving Mexican teams Guadalajara and San Luis have been postponed because of the swine flu outbreak and Colombia's refusal to act as an alternative venue.

The South American Football Confederation (CSF) had announced that the two sides would stage their home ties in Bogota but Colombian authorities rejected the plan.

San Luis are due to host Uruguayan side Nacional on May 6 in their second round first leg and Guadalajara were scheduled to play Brazilian champs Sao Paulo the same day.

The Copa Libertadores is the region's equivalent of the European Champions League, and was won last year by Liga de Quito of Ecuador.

The CSF had wanted to stage the games as part of a double-bill at Bogota's Campin stadium.

'Mull it over'

"The confederation wants to analyse, mull over the situation and find a way out," CSF spokesman Nestor Benitez said on Saturday.

"I wouldn't want to speculate over the outcome.

"The other second round matches will take place as established in the official program."

The virus is confirmed to have killed at least 16 people in Mexico, but officials estimate that as many as 101 people have died.

Tests are still being carried out on the other 85 dead.

Domestic football in Mexico has continued and the weekend's matches will all be played behind closed doors.

Mexican teams are not members of the CSF but three take part every year under a special agreement.

The Libertadores has a tight schedule with the second round, second leg ties due to be played next week, followed by the quarter-final first and second legs in successive weeks.

One solution which has been mooted would be for Guadalajara and San Luis to meet each other in the second round while Sao Paulo would face Nacional.