A bishop and several other people have been stabbed during a sermon in Sydney that was being streamed online.

The incident happened on Monday evening at the Christ The Good Shepherd Church in the suburb of Wakeley.

Police responded to reports that a number of people had been stabbed but said none of their injuries were life-threatening.

A man has been arrested and taken to an undisclosed location, police said.

Following the attack large crowds gathered outside the church, with unverified footage posted online appearing to show some attacking the building and emergency service vehicles.

Police said a large police response is under way and the public is urged to avoid the area.

The bishop who was attacked was named by local media as Mar Mari Emmanuel. His identity was later confirmed by the church, which is Eastern Orthodox.

The church said In a statement that a priest, Father Isaac, was also injured. Both were taken to hospital.

We ask for your prayers at this time, the church said.

We also kindly ask anyone at the Church premises to leave in peace, it added.

Local Mayor Frank Carbone was among those calling for calm.

I understand a lot of members in our community are really distraught but what is important is I believe that the bishop has been taken to hospital and should be okay, he told Sky News Australia.

According to AFP news agency, the neighbourhood is a hub for Sydneys small Christian Assyrian community, many of whom have fled persecution and war in Iraq and Syria.

In the livestreamed video on the sermon, a man dressed in dark clothing can be seen approaching the bishop before appearing to strike him with a weapon that was not immediately identified.

Several other people then attempt to intervene and screams of horror can be heard.

The injured people suffered non-life threatening injuries and are being treated by NSW Ambulance paramedics, police said in a statement.

Those hurt are all thought to be men aged between 20 and 70. The motive for the attack is unknown.

The stabbing comes days after six people were killed at a shopping mall in the same city. The attacker was later shot dead by a police officer.

There is no suggestion the two events are linked. (BBC: Text, Excluding Headline)