A Zimbabwean teachers' union is threatening to boycott classes every Friday if a number of their grievances including low pay are not addressed.

Progressive Teachers' Union of Zimbabwe president Takavafira Zhou announced the intended boycott at a press conference in Harare.

"We resolve to boycott classes and stay away from schools on Fridays beginning the 10th and 17th of July 2009. We will further boycott classes and stay away from schools on every Thursday and Friday starting on the 23rd of July if government does not respond to our action by the 17th of July 2009," Zhou said.

In addition to the boycotts, Zhou said teachers would march in all urban centers on the Fridays they would not be at work.

Zhou said his union has been pushed to act because the government had shown bad faith by not meeting any of the promises agreed to when the teachers went back to work earlier this year.

Some agreements, such as the re-hiring of teachers who had left the service with no questions asked have now been reversed. Some of those teachers who had taken up the offer, he noted, are now being asked to stop work while they are being in his words "vetted" by the government.  Another issue of major concern to the teachers Zhou said is the alleged deployment of ZANU-PF militia at schools by the ministry of youth.

"We are also disturbed by the presence of youth militias in schools and the militarization of the ministry of education through the appointment of former state security officers at head office as well as heads of schools," Zhou said.

Zhou said the deployment of the youth militia is particularly worrying as the youths are blamed for some of the violence that accompanied last year's general election campaign. President Robert Mugabe's Zanu-PF party has accused teachers of being supporters of the Movement for Democratic Change led by Morgan Tsvangirai who is now prime minister in the unity government.

Teachers returned to work in March after agreeing on a monthly salary of $100. The PTUZ says the agreement was that teachers' pay would be reviewed every month but to date this has not been done.  Attempts to get comment from the ministry of education were unsuccessful.