A councillor said she was left in tears after vandals defaced Australian and New Zealand Army Corps graves in west London.
Cllr Jane Palmer took a photo of the graves at the Harefield cemetery in Hillingdon after they were covered in blue spray paint overnight.
Police are appealing for information to try and catch the people who did it.
Insp Rob Bryan from Hillingdon police said anyone with information should not just standby and do nothing but should contact police.
Anyone with information should call police on 101 quoting reference number 0923805/15.