A group of Britons are believed to be among foreign nationals being held by Yemeni authorities for alleged links with al-Qa'ida.
Yemeni officials have claimed that some of those detained have connections with Umar Farouk Abdulmutallab, the "underpants bomber" who attempted to blow up a transatlantic airliner on Christmas Day last year, and Anwar al-Awlaki, a jihadist cleric who moved from the US to Yemen.
The arrests follow an investigation into the activities of an Australian woman by police in the capital Sanaa after information was supposedly passed to the Yemenis by the government in Canberra.
Shyloh Jayne Giddens, a Muslim convert who had studied Arabic and Islam in Yemen, was among several women questioned after documents were seized from her house.
Ms Giddens moved to Yemen with her seven-year-old son Omar and five-year-old daughter Amina four years ago. Two months ago the Australian government cancelled her passport for "national security reasons" at the request of David Irvine, the head of the Australian Security Intelligence Organisation.
Ms Giddens, from New South Wales, was teaching English in Sanaa at the time of her arrest. According to her lawyers, she denies having any terrorist links. The Australian government has refused to disclose the reasons behind the cancellation request or the nature of any information they passed to the Yemeni authorities.
At least two of the UK nationals being held are of Yemeni extraction, and others detained include American and French nationals as well as "Asians and Africans". The arrests took place, according to Yemeni officials, after information was received from Western intelligence services about the people involved, who have either been living in the country or were frequent visitors.
The Yemeni authorities have been carrying out periodic crackdowns on suspects since the bombing attempt by Abdulmutallab who, it is claimed, was radicalised during a stay in Yemen. He had also studied in London, but Yemeni authorities refused to say whether any of those being questioned had met him during his stay in the UK.Reuse content