JAKARTA, Sept 7 (Reuters) - Indonesia urged Malaysia on Friday to speed-up legal cases against employers accused of abusing Indonesian maids, saying strong punishment will serve as a deterrent.

The call came amid tensions between Jakarta and Kuala Lumpur over the alleged assault of an Indonesian karate referee by Malaysian police.

Two Indonesian maids had in recent months climbed out of the window of apartments where they worked using a rope, alleging abuse by their Malaysian employers.

Last month a Malaysian woman was charged with the murder of her Indonesian maid.

"Our wish is for the Malaysian government to take firm action that will have a deterrent effect," Foreign Ministry spokesman Kristiarto Legowo told a news conference.

"We are worried that similar cases will happen again without speedy and firm legal decisions," he said.

In a high-profile case three years ago, an Indonesian maid alleged that she was repeatedly burnt with an iron and scalded with boiling water by her Malaysian employer's wife. The trial on her case is continuing.

Anger is boiling in Indonesia after an Indonesian karate referee officiating an Asian championship said he was beaten up by police in the neighbouring country after he refused to show identification to prove he was not an illegal migrant.

Malaysian formally apologised for the incident after hundreds protested across Indonesia and some legislators called for a boycott of Malaysian products.

More than one million Indonesians work in more affluent Malaysia, including 340,000 who serve as domestic workers.

Malaysia says about 1,200 maids flee from the homes of their Malaysian employers each month, but it does not want to legislate on working conditions even though the migrants usually work long hours for low pay.