(Adds new trial)
RIYADH, April 21 (Reuters) - A Saudi Arabian court on Monday sentenced three more men to death, raising the number of people condemned for their involvement in a suicide attack on expatriate residential compounds in Riyadh in 2003 to eight, the state news agency reported.
Another 40 people were sentenced to terms of two to 35 years for assisting the attacks in northeastern Riyadh, which were part of a three-year campaign by al Qaeda that killed hundreds and was aimed at destabilising U.S. ally Saudi Arabia.
SPA said all the 40 convicted were Saudis with the exception of one Syrian.
On Sunday, the court sentenced five men to death and 37 others to jail for between three to 35 years as part of the same trial.
Riyadh crushed the campaign in 2006, detaining more than 11,000 people in its security prisons, it has said.
The remnants of that al Qaeda group fled to Yemen where in 2009 they joined local militants to form Al Qaeda in the Arabian Peninsula, now seen as one of the most dangerous branches of the movement around the world.
Saudi Arabia has put on trial hundreds of accused militants in recent months, jailing many of them and sentencing others to death on charges that they played a role in the 2003-06 campaign, or aided those going to fight in Iraq or Afghanistan.
The conservative Islamic kingdom has grown increasingly concerned about radicalisation this year because the war in Syria has spurred what they see as a surge in online militancy. They are worried about a new al Qaeda campaign of attacks. (Reporting by Reem Shamseddine; Editing by Angus McDowall and Nick Zieminski)