RIYADH — Saudi security authorities have arrested eight people for inciting Saudi youths to join extremist groups abroad, the Interior Ministry announced on Tuesday. “The arrests were made during a security operation in the Tumair governorate in Riyadh province on Monday,” a security spokesman for the Interior Ministry said in a statement carried by the Saudi Press Agency. The raids followed complaints from parents about people trying to recruit youngsters to join terrorist groups abroad. The ministry has said it will prosecute anyone who backs such groups financially or morally, or who seeks to promote them in the media and on social networks. The authorities have taken a tough stance against militant groups operating in the Kingdom and have made arrests of cells with links to extremist elements in different Arab countries. 18 militants sentenced The Special Criminal Court in Riyadh sentenced on Tuesday two groups of suspects to jail terms ranging from one and a half years to 20 years. The first group included 12 people — six Saudis, five Yemenis and one Palestinian. The charges against them included plotting to bomb a US diplomatic mission, embracing a deviant ideology, joining Al-Qaeda training camps in Yemen and Lebanon, funding terrorist activities, illegal possession of weapons, extending financial support to terrorists fighting abroad and facilitating travel of suspected militants to conflict zones to take part in fighting there. The court also sent five Saudis and an Omani citizen to jail after they were convicted of plotting to assassinate intelligence officers. They were also accused of disobeying the country's ruler, planning to open an arms training camp in Sudan and traveling to conflict zones to take part in fighting. They were sentenced to jail terms ranging from three to 20 years.