Malawian rights groups have postponed a nationwide anti-government demonstration scheduled for this week, saying they will wait for the outcome of a legal challenge against their plan.

A spokesman for the rights groups, Rogers Newa, told a news conference Tuesday the High Court is considering a petition by government loyalists for an injunction against opposition demonstrations.

Newa says Malawian rights activists want to allow that case and mediation efforts to proceed. The activists had planned to start the protests on Wednesday unless President Bingo wa Mutharika addressed their demands. No new date was announced for the demonstrations.

Malawian rights groups have called on President Mutharika to resolve chronic shortages of fuel and foreign exchange in the impoverished southern African nation. They also want him to declare his wealth. Mr. Mutharika had called on the groups to cancel the protests, warning they could turn violent.

Malawian security forces opened fire on anti-government protesters in three cities last month, killing 19 people. Some of the demonstrations had degenerated into looting.

In a statement Tuesday, global rights group Amnesty International called on Malawi to stop using live ammunition against demonstrators and allow people to express their opinions without fear of violent reprisals or arbitrary arrests.

The United States has frozen a $350 million aid package to Malawi in response to the violence.

Another major donor to Malawi, Britain, suspended aid earlier this year due to a diplomatic dispute arising from a leaked cable in which the British ambassador in Lilongwe said President Mutharika is “autocratic and intolerant of criticism.”