Riyadh, Saudi Arabia: Saudi authorities have arrested nine American citizens among 33 “terror” suspects rounded up over the past days, the Saudi Gazette newspaper reported on Sunday.

Four Americans were arrested on Monday and five others over the past four days, the paper reported citing an unidentified source.

The arrests also included 14 Saudis, three Yemenis, two Syrians, an Indonesian, a Filipino, an Emirati, a Kazakhstan national and a Palestinian, the paper said.

It did not say if any of the “terror suspects” was linked to the Islamic State group, which has claimed several deadly attacks against security and Shiites in the kingdom in recent months.

On Friday, a suicide bomber attacked a Shiite mosque in Eastern Province killing four people before worshippers disarmed and tied up his accomplice who had fired on them.

IS, a radical Sunni group that considers Shiites heretics, did not claim that attack.

The Saudi Gazette said some 532 IS suspects accused of plotting attacks in the kingdom are being questioned ahead of their trial at the criminal court in Riyadh.

They are members of six cells arrested in “pre-emptive” raids across the kingdom and include a Saudi woman and a Filipina, the paper said.