The trial of 20 prominent members of the banned Muslim Brotherhood - including several lawyers, doctors and academics - is resuming at a military base on the outskirts of Cairo.

The 20 defendants have been accused of belonging to an illegal group, harming social peace and trying to control Egypt's professional associations.

The trial represents the biggest case against the group since 1995.

It first opened in December last year, but was postponed immediately on procedural grounds.

Human rights activists

The arrest of the 20 members last October came as preparations began for elections to the country's lawyers' association.

It was the biggest sweep against the Muslim Brotherhood since more than 80 of its members were brought before military tribunals shortly before legislative elections in 1995.

Human rights activists both at home and abroad had appealed to the Egyptian Government not to try the 20 men in a military court.

In a letter to President Hosni Mubarak, the New York-based Human Rights Watch said no-one should face trial for planning to compete peacefully in elections to professional bodies.

Leaders executed

The Muslim Brotherhood is Egypt's oldest Islamist group and BBC correspondent Caroline Hawley says the authorities generally tolerate it because it does not advocate violence.

It was banned by former President Gamal Abdel Nasser after an attempt on his life in 1954, but has been largely tolerated since 1976.

Thousands of its members were held without trial over a 20-year period, and some of its leaders executed.

Since 1995, hundreds of Brotherhood members have been tried and scores imprisoned.

It insists that it is seeking to establish an Islamic state using peaceful means.