The Egyptian government plans a one-year extension to an emergency law that grants police sweeping powers of arrest, an official said on Sunday.

Hours earlier security forces detained 18 members of the opposition Muslim Brotherhood.

The official, who asked not to be named, said the government would shortly present to parliament a bill to extend the emergency law, which expires at the end of the month, after failing to prepare in time an anti-terrorism law that would encapsulate similar powers.

The emergency law, which has been in force since 1981, allows the police to hold people without charge for long periods and enables the authorities to refer civilians to military courts, where defendants have fewer rights.

Human rights groups say some detainees have been in custody more than 10 years without trial or charge. Along with the opposition, they accuse the government of abusing the emergency law to target political dissidents and predict it will continue the same practices when the anti-terrorism law is passed. The government denies these charges.

"Comparing the emergency law and the anti-terrorism law is like comparing the devil and the deep blue sea," Mohamed Habib, the Muslim Brotherhood deputy leader, told Reuters.

Hafez Abu Seada, secretary general of the Egyptian Organisation for Human Rights, said people had spent years in jail in defiance of court rulings that they be freed.

"There is no real political will to end the emergency law in Egypt," Abu Seada told Reuters.

The government said two years ago it would introduce the anti-terrorism bill before the emergency law expired, but it has not yet distributed any draft.

The proposal to replace emergency law with an anti-terrorism law was one of President Hosni Mubarak's promises during his re-election campaign in 2005. It came up again in the debate on constitutional changes approved by a referendum last year.

The amendments to the constitution included a ban on political activity based on religion, an article widely seen as an attempt to exclude the Brotherhood, Egypt's strongest opposition group, from mainstream politics.

The government says the non-violent Islamist group is a banned organisation, but the Brotherhood operates relatively openly despite regular police crackdowns. Its members, running as independents, won one fifth of the lower house of the parliament in 2005.

Police picked up nine Brotherhood members from their houses at dawn in the town of Abu Kabir in Sharkia province northeast of Cairo on Sunday, police sources said.

The town is preparing for a parliamentary by-election to replace a Brotherhood lawmaker who recently died.

Police detained five other Brotherhood members in the coastal city of Alexandria, and rounded up four others in the Nile Delta province of Menufia, the officials said.