Harare, Zimbabwe (CNN) -- A court in Zimbabwe ruled Monday that six of 45 political and civil society activists arrested last month on charges of plotting to topple President Robert Mugabe in a Tunisian-Egyptian style uprising face a trial on treason charges and could be executed if convicted.
"Merely listening to treasonous utterances is not criminal," said Harare Magistrate Munamato Mutevedzi as he freed 39 of the 45 activists who have been detained since February 19.
He said the six others must face trial because they had organized and spoken at the meeting. Mutevedzi ordered the six social and human rights activists held, including former Movement for Democratic Change Member of Parliament Munyaradzi Gwisai.
They now await a trial date at the High Court on treason charges, which carry the death sentence in Zimbabwe.
"You can apply for bail at the High Court since the offense you are facing is a scheduled offense which cannot be entertained by a magistrate court," said Mutevedzi, referring to the six.
Immediately after the ruling, the activists' attorney Charles Kwaramba told the court that his clients were being detained in solitary confinement while the women were being forced to work at the prison.
"We seriously object to this. They are still innocent and there is no need to punish them," said Kwaramba. "Their right of liberty is being seriously infringed. That amounts to slavery. It must not be allowed in a democratic society."
Last week, the United States expressed concern about their arrests and allegations by their lawyer that some of them were tortured.
The activists were arrested and charged with treason after they were caught watching footage of the protests that led to the ouster of Tunisian leader Zine El Abidine Ben Ali and Egyptian President Hosni Mubarak.
At least 12 of the activists were beaten with broomsticks on their buttocks and the soles of their feet, according to their attorneys.
Robert Mugabe, 87, has ruled Zimbabwe since 1980. Like Mubarak and Ben Ali, he has been accused of rigging elections and instituting repressive laws to tighten his grip on power.
Political observers have suggested the arrests may be an indication that authorities are worried that the changes sweeping across north Africa may inspire Zimbabweans to rise up.