TOKYO (AFP) - A local councillor in Tokyo has quit after writing "Drop dead!" during an angry exchange on Twitter, in another gaffe by local Japanese politicians in recent weeks.

Mr Hiromi Kaneko, 51, a communist member of the assembly in one of Tokyo's 23 districts, told Japanese media on Wednesday he stepped down at the behest of colleagues and supporters because the expression was "not appropriate" to be used by anyone, let alone a legislator.

"You ARE human scum. Drop dead! Before killing innocent civilians, you should drop dead!" Mr Kaneko, a representative in the upmarket district of Nakano, tweeted on July 6.

He was reacting to a series of comments from a supporter of the recent decision by Prime Minister Shinzo Abe's conservative government to permit the use of force in defending allies. The supporter said young jobless Japanese could help the country by taking part in such military action.

"I was so upset at the discriminatory remarks that I lost my composure," Mr Kaneko said.

Last month a conservative male member of the Tokyo metropolitan assembly apologised to a 35-year-old female colleague for telling her to get married when she was questioning city administrators about the status of mothers.

A 47-year-old male member of the prefectural assembly of Hyogo in western Japan stepped down last week.

He had become a worldwide Internet celebrity for crying like a toddler at a press conference while trying to explain his profligate use of public funds.