SYDNEY (REUTERS) - Australian Prime Minister Malcolm Turnbull called for calm on Friday (Oct 9) as police prepared for clashes between protesters at a planned rally outside a Sydney mosque that was attended by a teenager who killed a police officer a week ago.

Farhad Khalil Mohammad Jabar, 15, was shot and killed by police after he opened fire on police accountant Curtis Cheng as Cheng left police headquarters in the Sydney suburb of Parramatta last Friday.

The shooting and subsequent arrest of five people in raids in Sydney has stoked anxiety over further militant violence and retaliatory attacks against Muslims.

Turnbull called mutual respect between faiths "the glue that binds this very diverse country together" and blamed anti-Muslim protesters for stoking divisiveness. "Those who do that are making the work of the police and security services ... who seek to prevent violent extremism much harder," he told reporters in Sydney.

Australia, a staunch ally of the United States and its battle against Islamic State in Iraq and Syria (ISIS) militants, has been on heightened alert for attacks by home-grown radicals since last year.

Turnbull also announced a meeting set for next week to address countering extremism in the wake of last week's shooting. "Friday's attack in Parramatta was a shocking reminder of the consequences of radicalisation," he said in a statement.

Protests between anti-racist groups and anti-Islam parties have turned violent several times this year in different Australian cities.

Parramatta police commander Superintendent Wayne Cox told reporters he did not expect any violence on Friday but said 75 additional officers had been deployed. Streets were blocked off and Cox urged citizens to avoid the area unless necessary.

In September, police shot dead a Melbourne teenager after he stabbed two counter-terrorism officers. Last December, two hostages were killed when police stormed a central Sydney cafe to end a 17-hour siege by a lone gunman.

Earlier this month, a 15-year-old British boy was sentenced to life in prison for inciting an attack on a World War One commemorative event in Australia from his bedroom in northern England.

The discovery of the boy's actions sparked a massive police operation in Melbourne that led to the arrest of five teenagers who were planning an ISIS-inspired attack, authorities said.