By Asma Alsharif
CAIRO (Reuters) - Thousands of Islamist protesters clashed with opponents as they rallied on Friday to demand a purge of Egypt's judiciary, a sign of rising tension between the Islamist government and legal organs seen as a redoubt of old regime influence.
Thirty-nine people were injured in a bout of stone-throwing, and occasional gunshots outside the High Court, according to witnesses and a security source cited by state media. Police use tear gas to quell the disturbances.
Islamist President Mohamed Mursi's rule, in which he has repeatedly locked horns with judges over decrees seen by liberal and leftist opponents as moves to entrench Islamist domination, has divided many Egyptians and led to repeated street violence.
Friday's rally was called by the Muslim Brotherhood and its affiliated Freedom and Justice Party which propelled Mursi to power in last year's election after the popular uprising that overthrew Hosni Mubarak in 2011.
Friction between the government and judiciary worsened in March when the Administrative Court ordered the cancellation of a Mursi decree calling for parliamentary elections, forcing a delay in voting due to have begun in April.
Later that month an appeals court ordered the justice ministry to reinstate the former prosecutor general who had been sacked by Mursi in November, saying that move was illegal.
In statements by the FJP and the Muslim Brotherhood ahead of Friday's protest, they called for what they said would be an independent judiciary by passing new legislation and removing corrupt members of legal institutions.
They further demanded prosecutions of those involved in killings of anti-Mubarak demonstrators in 2011.
"The people want to sack the Justice Minister and carry out revolutionary trials!" said an Islamist banner at the rally.
"This protest (was) essentially part of the Muslim Brotherhood's anti-judiciary campaign," said Gamal Soltan, political science professor at the American University in Cairo.
"I don't believe the Brotherhood believes in the separation of power. They want to have complete control over the country and this means the presidency, legislation, police, courts. But they are just taking it one at a time and now it is the time for the judiciary," he said.
The opposition National Salvation Front, an umbrella grouping of liberals and leftists, criticised Friday's Islamist rally as "a new, aggressive attack on the judicial authority".
Mursi has said he is striving to rid the state of Mubarak-era appointees obstructing the transition to democracy.
On April 13, a judge who got his post under Mubarak aborted the former autocrat's retrial for complicity in murder of protesters in 2011 and referred it to another court, causing a delay until May 11 and considerable public anger.
On Monday, another judge ordered Mubarak's release on bail but he has remained in custody in a military hospital on separate charges of alleged corruption.
The new Judicial Authority Law proposed by the Muslim Brotherhood, if passed, would reduce the retirement age for judges from 70 to 60 years, easing a makeover of the judiciary.
"By doing that they will send about 3,500 judges to retirement. This is out of a body of a little more than 10,000, so almost one third of the entire court system," Soltan said.
(Additional reporting by Ahmed Tolba; Editing by Mark Heinrich)