That number is almost three times higher than previous estimates.

The court, called the Special Jurisdiction for Peace, is investigating crimes and atrocities committed during half a century of armed conflict between government troops and the Revolutionary Armed Forces of Colombia (FARC), Marxist rebels who laid down arms following the historic 2016 peace accord.

The tribunal described the killings as "illegitimate deaths presented as combat fatalities," which are known in military circles as "false positives."

Until last year, the public prosecutor's office had acknowledged 2,249 executions of civilians between 1988 and 2014 -- the majority of which were carried out between 2006 and 2008, during the presidency of Alvaro Uribe, the political mentor of current President Ivan Duque.

Although the military high command has always denied there was a systematic policy of declaring "false positives," some soldiers and officials have told the court that they were put under pressure by superiors to inflate the success of their military operations against rebels.

The court said most of the killings took place in northwestern Antioquia department where soldiers and right-wing paramilitaries fought battles with left-wing rebels.

It said the IV Brigade of the army, which operated in the region, "could be responsible for 73 percent of the deaths identified in the department between 2000 and 2013."