A strong earthquake shook the Colombian capital Bogota on Thursday, setting off sirens and sparking brief panic on the streets but apparently without causing injuries or material damage.

The Colombian Geological Survey (CGS) put the magnitude of the quake at 6.1, while the US Geological Survey (USGS) reported it at 6.3.

The Colombian agency said the earthquake struck at 12.04pm (1704 GMT), with its epicentre in the town of El Calvario, 40 kilometres southeast of Bogota.

It was followed by a 5.9-magnitude aftershock, the agency posted on social media.

Buildings shook and sirens sounded as thousands of panicked residents poured into the streets of the capital, gripping their cellphones as they called loved ones, AFP journalists observed.

"Strong tremor in Bogota. Let's remain calm and cautious. Please take all precautions against possible aftershocks. Calm, serenity and caution," said the mayor of the capital, Claudia Lopez, on the X social network.

She said there were only "reports of people trapped in elevators and other minor events. Nothing serious." 

Social media users reported feeling the quake in the cities of Villavicencio, Bucaramanga, Tunja, and Ibague, all near the epicentre.

US ambassador Francisco Palmieri was giving a speech at a Bogota hotel when the quake hit, as seen in a video of the session, attended by President Gustavo Petro. Palmieri stopped talking to ask out loud in English if there had been an earthquake, then resumed speaking, with a smile. The hotel was not evacuated. 

A landslide was reported in Villavicencio, while only the windows of homes and businesses were reportedly affected in El Calvario, according to an update from the National Unit for Disaster Risk Management. 

Central Colombia is very seismically active and features one of the country's main geological faults.

In 2008, a 5.5 magnitude quake centred in El Calvario left 11 people dead.