US officials say they do not believe nine US citizens were among 33 suspects detained on terrorism charges in Saudi Arabia over the past week, as reported by a Saudi newspaper.
The English-language daily Saudi Gazette, citing an unnamed source, on Sunday reported that four Americans were detained last Monday, followed by another five in the following days.
Saudi authorities also detained 14 Saudis, three Yemenis, two Syrians, an Indonesian, a Filipino, a United Arab Emirates citizen, a Palestinian and a citizen of Kazakhstan, the report said.
Six US officials told Reuters that the US government could not confirm that any Americans were among the 33 suspects detained.
However, two officials said US authorities were still checking names against databases.
Saudi authorities were also investigating the citizenship of those detained, one of the officials said.
None of the US officials was authorised to speak publicly, and the US embassy did not immediately respond to a request for comment.
Saudi Arabia in 2014 declared Islamic State a terrorist organisation and has detained hundreds of its supporters.
The group, which controls territory in Iraq and Syria, has staged a series of attacks in the kingdom.
On Friday an attack at a Shi'ite Muslim mosque in Saudi Arabia's al-Ahsa district in Eastern Province killed four people and injured 18, the latest in a string of attacks claimed by Sunni jihadists that have left over 50 dead in the past year.
The website of the Interior Ministry's militant rehabilitation centre listed four US citizens as having been detained on January 25 and four more over the previous three months.
It did not list any more recent detentions.
The Interior Ministry spokesman directed Reuters to the website, which gives information on all people detained as militant suspects, but gave no further comment.