Pope Francis, who has had a mild flu in recent days, was taken to a hospital in downtown Rome on Wednesday, reviving concerns about the 87-year old pontiff’s health. The Vatican said in a statement that he had gone for “some diagnostic tests,” but did not offer details about a visit that lasted less than an hour.

At his weekly audience earlier in the day, Francis had apologized to those present, saying that an assistant would read his speech because he still had “a slight cold.” After the audience ended, the pope spent about an hour greeting the faithful while sitting in a wheelchair that he has increasingly used in recent years.

Traffic police officers at the Gemelli Hospital on Tiber Island said that Francis arrived around 11:20 a.m. on Wednesday and left about 40 minutes later.

The pope has been under the weather for several days. On Saturday, Francis’s public audiences were canceled “as a result of a slight flu,” according to the Vatican. The next day, he recited the Angelus prayer and blessing from his apartment overlooking St. Peter’s Square, but his audiences were again canceled on Monday because his “flu symptoms persisted, without a fever,” the Vatican said at the time.

Francis also did not participate in the traditional procession at the start of Lent two weeks ago.

Francis’s health has been a source of concern. The pontiff has been hospitalized three times in two years, most recently in June, when surgeons operated on an incisional hernia, typically a consequence of previous operations, that had been causing painful intestinal blockages. He also had colon surgery in 2021, and in March last year he was hospitalized because of a respiratory infection.

In November, under doctors’ orders, Francis did not attend the United Nations climate summit in Dubai after a bout of flu and lung inflammation. He lost part of a lung to an infection as a teenager.

Jason Horowitz contributed reporting.