By Jeremy McDermott
BBC News, Medellin
Recent attacks by Colombia's Marxist rebels display the training of IRA members captured in the country in August 2001, an army chief has said.
The three Irishmen each received 17 year sentences
Gen Carlos Ospina said there was no doubt Revolutionary Armed Forces (Farc) rebels were using IRA techniques in a counter-offensive launched in February.
The three Irishmen were convicted of helping train Farc rebels in explosives and terrorist techniques.
They are now on the run and thought to have skipped the country.
The armed forces chief said the Farc guerrillas were employing new technology in the home-made mortars they had recently used to bomb towns in the south-western province of Cauca.
Security forces had seized rebel grenades that were copies of those manufactured by the Provisional IRA, Gen Ospina added.
The guerrilla actions have caught the military by surprise.
The three Irishmen caught the Colombian police similarly by surprise when they disappeared after their convictions.
James Monaghan, Niall Connolly and Martin McCauley vanished while on bail in December awaiting the outcome of an appeal against their 17-year sentences.
Their whereabouts remain unknown and an international arrest warrant has been issued for them.