Bogota Mayor Gustavo Petro was operated successfully for blood clots on the brain and remains "under strict medical observation," according to the first medical report from the clinic where he was admitted on Friday.

The medical director of the Santa Fe Foundation, Adolfo Llinas, told reporters that "the operation was successful and the mayor is recovering under strict medical observation."

He added that Petro "has retained his full cognitive functions."

He said the mayor was hospitalized Friday "with a severe headache" and following doctors' evaluation "underwent surgery to drain a subdural hematoma," or bleeding in the brain.

The doctor provided no further details about how long it would take for Petro to recover or if he had experienced any additional symptoms.

From his Twitter account, Colombian President Juan Manuel Santos said that "we wish the mayor of Bogota, @petrogustavo, a speedy recovery."

The acting mayor, Guillermo Asprilla, told reporters that he could speak to them with "complete calm about the condition of the city and of the mayor."

He said that Petro is surrounded by his family and that "we're going ahead, under his guidance, with the usual work of government."

He also expressed gratitude for the "companionship and solidarity" of President Santos and said that as the hours go by, further medical reports will be forthcoming to keep everyone up to date on the state of Mayor Petro's health.

On Friday the private secretary of the Bogota mayor, Jorge Rojas, had said that Petro was hospitalized for respiratory problems.

He added that because of health problems, Petro canceled his attendance at the Rio+20 summit on climate change in Brazil.

Petro, a former guerrilla of the defunct April 19 Movement, or M-19, took office as mayor of Bogota last Jan. 1 for the leftist Progresista Party that he founded and leads.

Also hospitalized is Colombian Vice President Angelino Garzon, who was admitted "preventively" last Thursday to undergo "routine tests," a press release said.

Though Garzon promised "to report on the evolution of his recovery," no medical report has been forthcoming either from his office nor from the Reina Sofia Clinic where he is being attended.

The Colombian high official had to be hospitalized on Aug. 9, 2010, two days after taking office together with President Santos, due to cardiac pains that kept him in repose for several weeks. Since then he has had to undergo regular medical exams. EFE