The Singapore Armed Forces withdrew its delegation from the Jakarta International Defence Dialogue (JIDD) exhibition after the modern Indonesian marines were seen on Wednesday wearing name badges reading Usman and Harun, Today Online reported.
Osman Mohamed Ali and Harun Said were hanged in Singapore for the 1965 bombing of an office building that killed three people, at a time when Singapore was part of Malaysia, which had tense relations with Indonesia.
The marines on Wednesday were stationed at a booth with a model of the warship KRI Usman Harun, whose naming after the bombers in February reignited the dispute.
Singaporean officials expressed their disappointment to the Indonesian Foreign Ministry and the military.
"The posing of the two marines at the JIDD did not reflect the spirit of Indonesian Foreign Minister Marty Natalegawa’s comments of 11 February 2014 that no ill-will or malice was intended towards Singapore," Singapore's Ministry of Foreign Affairs said in a statement.