SAN FRANCISCO, Jan 5: With a registration deadline less than a week away, Muslim immigrants in the Silicon Valley are worried that visitors from Afghanistan, Lebanon and 11 other countries may not register as part of a new US security programme because they fear detention or deportation.

The Immigration and Naturalization Service (INS) took hundreds of men from five Middle Eastern countries - Iran, Iraq, Libya, Sudan, and Syria - into custody after the first registration deadline last month, primarily for overstaying their visas or registering late. These infractions rarely resulted in detention before Sept 11, 2001.

Those under detention include 25 people from the Silicon Valley.

Silicon Valley immigrant-advocacy groups say that even visitors who are here legally on valid visas are nervous about the registration process and a Jan 10 deadline, which applies to male visitors from 13 countries - Afghanistan, Algeria, Bahrain, Eritrea, Lebanon, Morocco, North Korea, Oman, Qatar, Somalia, Tunisia, United Arab Emirates and Yemen.

Pakistani and Saudi nationals are required to register between Jan 13 and Feb 21. Fearing more detentions, immigrant-advocacy groups hastily set up a legal clinic in San Francisco this weekend.

Beginning on Monday, a civil rights group will track how many register and how many are detained. A protest outside the INS office in San Francisco is scheduled for Jan 10.