SAN SALVADOR (Reuters) – Mexico rejected an accusation by Salvadoran President Nayib Bukele on Monday that it had allowed a dozen people with coronavirus to board a flight to San Salvador, saying medical staff had found no evidence of the virus on the travelers.

Earlier, Bukele abruptly suspended all passenger flights to San Salvador after making his assertion on Twitter, describing Mexican authorities as “irresponsible.”

The Salvadoran president did not provide evidence for the claim, which Mexican Deputy Health Minister Hugo Lopez-Gatell said turned out to be “totally false.”

In an evening news conference, Lopez-Gatell explained that 12 Salvadorans en route to San Salvador from Chicago had raised suspicions because they were wearing protective masks. Tests showed that none of them had the virus, he added.

Foreign Minister Marcelo Ebrard replied directly to Bukele on Twitter with news that medical authorities had determined the passengers for the Avianca flight were virus-free.

“You will be delighted. Best regards,” Ebrard wrote.

Bukele, who also complained to Ebrard on Twitter that Mexico had given political asylum to an unnamed man wanted in El Salvador, made his accusation before the flight took off.

Avianca canceled the flight and said passengers had not boarded. The airline issued tweets thanking Bukele for alerting it to the presence of coronavirus patients on the passenger list.

Bukele later said San Salvador’s airport had reopened after airlines accepted new health protocols. But flights from Mexico would remain suspended for the time being, he added.

(Reporting by Nelson Renteria and Frank Jack Daniel in Mexico City; Editing by Richard Pullin and Clarence Fernandez)