Saudi Arabia said on Sunday that it had arrested 135 people on "terrorism-related charges."
The suspects included 109 Saudi nationals and 26 foreigners, according to the Saudi Interior Ministry.
"Security agencies had managed to arrest a group of suspects different in thought, but united in terrorism," Interior Ministry spokesman Mansour al-Turki said.
He was quoted by the official Saudi news agency as saying that the 26 foreigners included 16 Syrians; three Yemenis; an Egyptian; a Lebanese; an Afghan; an Ethiopian; a Bahraini; an Iraqi, and a man who did not carry the nationality of a specific country.
Al-Turki said 40 suspects were arrested in different parts of Saudi Arabia for travelling to conflict zones and receiving training in terrorist operations and then returning to Saudi Arabia with the aim of carrying out attacks.
He added that 54 suspects had links with extremist organizations and supported these organization either through finance or sending recruits.
Seventeen suspects were involved in riots, attacks against policemen and the possession of arms, al-Turki said.
He added that three suspects were arrested in the eastern province of Qatif after recruiting people and sending them to receive training in terrorism abroad.
He noted that the remaining 21 suspects were arrested on charges of entering and trying to get out of Saudi Arabia in an illegal manner.