Thirty-six suspects accused of helping the rebel Justice and Equality Movement group stage a May 10 attack in the Sudanese capital are being tried in special anti-terrorism courts that have proved arbitrary and biased against the defendants, Human Rights Watch said Wednesday.

"The Sudanese authorities should stop denying defendants their right to a fair trial, otherwise the trials are no more than a show," said Georgette Gagnon, Africa director at Human Rights Watch. "The authorities should allow the defendants full access to their lawyers."

The defendants have been charged as a group under a 2001 anti-terrorism law, which, Human Rights Watch said, is being used for the first time in the country after the government classified the movement as a terrorist group. The charges carry the death penalty on conviction.