There have been a string of incidents at locations across Wellingborough in recent days.
Offensive words targeted at white people were written in big letters across the front of the memorial in Broad Green, Wellingborough, between Saturday night a
nd Sunday morning.
The white stone memorial lists the names of Wellingborough soldiers who died in the First and Second World Wars.
The offensive words were temporarily covered with a plastic recycling bag and on Sunday a member of the public attempted to wash the graffiti off, although it was still clearly visible. The graffiti was finally removed yesterday.
Councillor Robert Hawkes, ward councillor for Swanspool which includes Broad Green, said: "It's not what I want to see on my war memorial. It's disgraceful. It's illiterate, mindless stupidity, probably fuelled by alcohol.
"Graffiti has no place anywhere, but a war memorial is one place you definitely wouldn't expect to see it. You would think that people would respect a memorial like that."
Graffiti was also sprayed across a building in Kiln Way, on the Queensway estate in the town, on Saturday night and police believe the two incidents could be connected.
A police spokesman said: "We are appealing for information about offensive graffiti which was daubed in the area of Broad Green and Queensway in Wellingborough."
Noel Hubbard, 81, of Wilby Park, Wilby, was angry to hear of the vandalism.
He said: "I think it's disgusting.
"The youth of today have no respect for other people's property, whether it's private, council or otherwise."
Insp Vaughan Clarke, sector commander for Wellingborough, said: "We believe the recent incidents of offensive graffiti found in a number of locations were committed by the same person and are isolated incidents that took place on the same day.
"We are conducting inquiries to identify the offender and are working closely with the local authority to ensure that such graffiti is removed as soon as possible.
"Hate crime will not be tolerated by Northamptonshire Police."
Witnesses, or anyone with information, can call Northamptonshire Police on 03000 111 222 or Crimestoppers, anonymously, on 0800 555 111.