Eight Darfur rebels convicted and sentenced to death for attacking the Sudanese capital have appealed their sentences.

Defense lawyers for the rebels said Tuesday that they have filed appeals with Sudan's Constitutional Court.  The lawyers argue that special courts set up to try alleged rebels are unconstitutional.

The lawyers say they will file appeals for another 22 accused rebels also given death sentences.

The rebel Justice and Equality Movement, JEM, attacked the capital, Khartoum, and its twin city Omdurman on May 10.  More than 200 people were killed in the fighting.

Sudanese President Omar al-Bashir has pardoned about 90 juveniles arrested by the authorities following the JEM attack.  In June, Sudan began proceedings against 39 other suspected Darfur rebels on terrorism charges.  

The JEM has argued the special courts are illegal.

The JEM is considered the largest and strongest of the many rebel groups in Darfur.  Fighting in the region has continued for more than five years, killing more than 200,000 people and displacing 2.5 others.

Some information for this report was provided by Reuters.