Thousands of immigrants in the United States are rushing to comply with a deadline to register with authorities under anti-terror laws introduced following the 11 September attacks.

Friday is the cut-off for males over the age of 16, from 13, mainly Muslim countries, who are not permanent US residents, to have registered with the Immigration and Naturalisation Service (INS).

Countries affected

Afghanistan Algeria Bahrain Eritrea Lebanon Morocco North Korea Oman Qatar Somalia Tunisia The United Arab Emirates Yemen

They may be detained or deported if their visas have expired or if they have otherwise violated US immigration law, or they may be arrested if they fail to register.

The controversial "special registration" effort has attracted widespread condemnation from civil rights groups and has been the subject of numerous legal challenges.

On Thursday a lawsuit filed by US-Muslim groups following the first wave of registration, seeking a block on further such detentions, was dismissed by a US federal judge.

The judge said that the men had been arrested legitimately by the INS for breaking immigration laws.

Fingerprinted

Under the scheme male foreign nationals from countries identified as harbouring terror groups must register, be fingerprinted and questioned.

Several cities reported queues of people from the early hours of Friday morning, despite many voicing concern that they may be detained.

I'm totally scared... If I go, I can get arrested, and if I don't go, I can get arrested, in both cases, it is bad for me Immigrant Chedli Fathi

Up to 1,000 men from Iran, Iraq, Libya, Sudan and Syria, who came forward in earlier registration processes, are currently being held by US authorities, according to human rights advocates.

US officials however, put the number at around 250.

Men from Pakistan and Saudi Arabia must register by 21 February.

Immigrant's fear

Many illegal immigrants fear that they may suffer the same fate as those being held.

"I'm totally scared," 28-year-old Chedli Fathi, whose student visa expired in 2001, told the San Francisco Chronicle newspaper.

"If I go, I can get arrested, and if I don't go, I can get arrested. In both cases, it is bad for me."

Earlier detentions led to angry demonstrations

Muslim community leaders in Los Angeles, California - one of the first states where Middle Eastern men were obliged to register - said they were deploying around 160 human rights monitors to immigration stations in the city.

It was in Los Angeles - home to a sizeable Iranian community - that the majority of detentions in December last year took place.

The arrests led to mass protests, with many comparing the process to the internment of Japanese-Americans during World War II.

Human rights groups said that many of the detained men were genuinely going through the complex process of obtaining permanent residency status, or a so-called "green card".

The arrests also became a public relations disaster for the Bush administration, with critics saying that it is unlikely that terrorists would take part in a voluntary registration programme.