The Malaysian authorities have issued what they say is a final warning to organisers of a nationwide anti-government protest movement.

The Home Ministry said rallies being organised by the group -- the Malaysian People's Justice Movement -- were illegal and its leaders risked fines or imprisonment if they continued their activities.

One member of the protest group Syed Hussein Ali described the warning as a desperate move by the government to protect its interests: he said it was an example of what the movement was fighting against.

The BBC south-east Asia correspondent, however, says the threat of a crack-down will not be taken lightly.

The warning comes amid reports that further protests are planned for Saturday ahead of the trial on Monday of the sacked deputy prime minister, Anwar Ibrahim, on charges of corruption.

The Justice Movement was formed last month to push forward the campaign for political reform intiated by Mr Ibrahim before his arrest.