The operation was launched on May 1 and ended on May 3, 1995. During less than 32 hours Croatian troops and police regained control of 500 square kilometres of land, including the main west-east motorway and the railway line leading to Eastern Slavonia.
About 7,200 troops and police officers took part in the liberation of Western Slavonia, of whom 42 were killed and 162 wounded. It was the first time during the 1991-1995 Homeland War that the Croatian Air Force had used airstrikes on a larger scale, and the enemy was further surprised by tanks that were brought in by rail and deployed in combat.
The ceremony was attended by top state officials -- President Kolinda Grabar-Kitarovic, Parliament Speaker Josip Leko and Prime Minister Zoran Milanovic, as well as by delegations of the Parliament and the Government.
The names of the soldiers and policemen killed in the operation were read at a memorial service. The ceremony also included a parade of army and police units, and two Air Force jets flew over Okucani at the start of the event.
Okucani is located about 130 kilometres southeast of Zagreb. During the war it was the centre of the Serb rebellion and a staging area for terrorist attacks in Western Slavonia.