Sana'a, Yemen - A Yemeni court of appeals on Monday upheld a death sentence for a Shiite rebel and jail terms for 12 others for plotting attacks in support of rebels who fought army forces in northern Yemen for more than four years.

The court confirmed the initial death sentence against the main defendant, Ja'afar al-Merhebi, who was convicted of killing two police officers when they raided his house in the capital Sana'a in 2007.

Presiding judge Muhammad Said al-Hakimi said the court also upheld prison sentences of 10 years for four men and terms of eight years for two others.

Five other men received sentences of six years in prison, while a final man had his sentence reduced from five years to three.

Sporadic but fierce clashes between the Shiite rebels and the army have left hundreds of soldiers and insurgents dead since the fighting erupted after the group was founded in mid-2004 by Shiite rebel leader Hussein Badruddin al-Houthi, who was killed by the army in September 2004.

After the verdict was pronounced, al-Merhebi shouted "Death to America, death to Israel, curse on Jews and victory to Islam." The slogan is the trademark of the rebel Shiite group Believing Youth, whose armed members fought government forces in the northern province of Saada for more than four years.

Also involved in the case was Abdul-Kareem al-Khaiwani, former editor of the Shura opposition weekly, who had previously received a six-year jail sentence. He was convicted of disseminating pro-rebel propaganda to local and foreign media.

Al-Khaiwani served eight months of his term before President Ali Abdullah Saleh pardoned him last year.

When the trial began in July 2007, prosecutors said the defendants had been involved in a conspiracy to blow up vital government and military buildings in Sana'a. Prosecutors also said the men had prepared remote-controlled explosive devices to carry out the attacks and had planned to poison the water reservoirs of police and military posts.

Last July, Saleh announced the end of the conflicts in Saada, a remote mountainous region on the border with Saudi Arabia, 230 kilometres north of Sana'a.

Authorities have accused the rebels of trying to reinstall the rule of imams, which was toppled by a republican revolution in northern Yemen in 1962. (dpa)