A Colombian right-wing presidential candidate who was shot during a campaign event in Bogota has successfully undergone initial surgery, the city's mayor said on Sunday.

39-nine-year-old senator Miguel Uribe was speaking to supporters in the capital when a gunman shot him twice in the head and once in the knee before being detained.

A security guard managed to detain the suspected attacker, a minor who is believed to be 15 years old.

Uribe was airlifted to hospital in "critical condition" and underwent a "neurosurgical" and "peripheral vascular procedure," the Santa Fe Clinic in Bogota confirmed.

He "overcame the first surgical procedure," Bogota mayor Carlos Fernando Galan told media, adding that he had entered "the critical hours" of recovery.

His wife, in an audio recording shared with media, said "he came out well from the surgery."

The motive for the attack is not yet publicly known. Colombia's defense minister Pedro Sanchez vowed to use law enforcement's full capabilities and offered a roughly US$725,000 reward for information about who was behind the shooting.

In a video address to the nation posted on social media, President Gustavo Petro also promised investigations to find the perpetrators of the "day of pain".

"What matters most today is that all Colombians focus with the energy of our hearts, with our will to live ... on ensuring that Dr Miguel Uribe stays alive."

Uribe, a strong critic of Petro, is a member of the Democratic Center party, which announced last October his intention to run in the 2026 presidential election.

Authorities said there was no specific threat made against the politician before the incident. Like many public figures in Colombia, Uribe had close personal protection.

The country is home to several armed guerrilla groups, powerful cartels and has a long history of political violence. (AFP)