JEDDAH, Saudi Arabia (Reuters) - Saudi authorities arrested a group of suspected al Qaeda-linked militants in Riyadh, the Interior Ministry said in a statement on state news agency SPA on Sunday.
"After intense surveillance of the cell it was revealed that they have reached an advanced stage in their plan to implement their goals, which include preparing and setting explosives and testing them outside of Riyadh," the ministry said.
Security forces arrested six members of the cell - all Yemeni nationals - after arresting their leader, a Saudi, and questioning him, the statement said.
The ministry has worked with Western intelligence agencies to foil al Qaeda attacks planned in Yemen, and although a 2003-2006 al Qaeda campaign inside Saudi Arabia was suppressed, the group's regional wing based in Yemen, al Qaeda in the Arabian Peninsula (AQAP), has sworn to bring down the ruling al-Saud family.
Saudi Arabia has arrested thousands of suspected militants since the 2003-2006 attacks on residential compounds for foreign workers and on Saudi government facilities, killing dozens.
The United States has poured aid into Yemen to stem the threat of attacks from AQAP and to try to prevent any spillover of violence into Saudi Arabia, the world's top oil exporter.
In 2006 and 2008 security forces foiled planned attacks by militants against oil installations in its Eastern Province.
The latest arrests and investigation had also revealed a connection with a militant cell in Jeddah and led to the arrest of one of its members, a Saudi, who is accused of preparing chemicals to be used in explosive devices, the ministry said.
The last attempted attack in Saudi Arabia that was made public was a 2010 attempt to assassinate Prince Mohammed bin Nayef, the assistant Interior Minister and head of the security service.
(Reporting by Asma Alsharif; Editing by Louise Ireland and Angus McDowall)