Police believe that some of the Albanian fugitives who have been on the run since they broke out from Trikala Prison in March were attempting to help convicted killer Alket Rizai escape from jail as well.
Sources told Kathimerini that they found 5.5 kilos of explosives and hundreds of bullets for Kalashnikov assault rifles in one of the cars the fugitives abandoned in central Greece.
However, police believe there is further evidence linking the fugitives with a breakout attempt.
One of the two men killed by police officers on Tuesday as they attempted to catch the fugitives was Flamur Sinani, himself an escapee since 2006.
They believe Sinani was instrumental in helping the 11 Albanians escape from Trikala Prison earlier this year.
Rizai, who escaped by helicopter from Korydallos Prison in 2006 and 2009, is being held at Domokos jail, where authorities have been on alert over the past weeks, sources said.