An appeals court in Mexico has overturned the convictions of more than 20 people accused of carrying out a 1997 massacre in which 45 people were killed for allegedly supporting Zapatista guerrillas.

A total of 24 people had received 35-year sentences for their alleged role in the December 1997 massacre in Actael, a suburb of Chenalho in Chiapas state.

The massacre caused international outrage and forced the resignation of Mexico's interior minister, and the governor of Chiapas.

Among those whose convictions have now been overturned is Jacinto Arias Perez, former major of Chenalho and a regional director of the ruling Institutional Revolutionary Party (PRI).

Sectarian divide

All the victims were Catholic native Indians, most of them women and children.

The alleged perpetrators were Indians from neighbouring villages who supported the PRI and were opposed to the grass-roots rebellion of the Zapatista guerrilla movement, which began in 1994.

The National Fraternity of Evangelical Christians, a protestant group, has taken up the defence of those under suspicion of involvement in the massacre.

Arturo Farela, director of the group, said the appeals court had found the original charges inconsistent.

The suspects had been charged with murder, assault and illegal possession of firearms restricted for military use.

"Federal prosecutors should give up these charges, which in any case are unsustainable, because the case they presented was inconsistent and should not have been aimed at so many indigenous people," he said.

"The convictions were overturned for obvious reasons, like the implication of 88 indigenous people in the killing of 45 people, with only 13 firearms," said Mr Farela.

The 24 whose sentences have now been overturned are among 88 suspects being held in prison in connection with the massacre.