POLICE spoke to two youths late last night after a suspicious fire between the Warrnambool water treatment plant and the pony club in Albert Park Reserve.
Sergeant Chris Moloney said Warrnambool police were called about 11.30 to the blaze at the north-west corner of the treatment plant in Grieve Street.
Warrnambool fire brigade members also attended and put out the fire, which started near cyclone fencing and spread about 20 metres along the northern and western boundaries of the treatment plant.
Only grass was damaged.
Sergeant Moloney said a 10-year-old and 12-year-old boy were spoken to by police officers and taken back to their homes in the Wanstead Street area.
"Police are making follow up inquiries but we are calling on anyone with information to contact the Warrnambool police crime investigation unit or Crime Stoppers on 1800 333 000," he said.