Police are appealing for witnesses to two fires in Dandenong.
They said a firebug lit hard rubbish outside a Power Street house about 11.15pm on Thursday 24 May.
Someone set fire to a dumpster bin at Dandenong Primary School in Foster Street a short time later.
CFA crews attended and extinguished both fires.
Police said they were deliberately lit using unknown accelerants and were likely to be linked.
They urged anyone with information to call Crime Stoppers on 1800 333 000.
