Complex sentence: Nick Spanos and Stephen Melrose were innocent Australian tourists killed in Holland by the IRA on 27 May 1990 having mistaken them for off-duty British soldiers.
Split into simpler sentences: Nick Spanos and Stephen Melrose were Australian tourists killed by the IRA on 27 May 1990. The killings were claimed by the IRA, who believed Spanos and Melrose were off-duty British soldiers.