Sydney, April 16 (IANS/DPA) Australian police are treating a stabbing at a Sydney church as a terrorist attack, New South Wales Police Commissioner Karen Webb said on Tuesday.

Police were called to Christ The Good Shepherd Church in Wakeley, western Sydney, on Monday evening, following reports of a stabbing where two people had been injured, Webb said.

A 16-year-old boy, who had been restrained by members of the public, was arrested by police.

Webb said the boy allegedly made comments as he launched the attack. "After consideration of all the material, I declared that it was a terrorist incident."

The boy was taken to hospital where he remained under police guard. He had undergone surgery for injuries sustained during the alleged attack.

While police were responding to the incident, a large crowd gathered outside the church, Webb said.

Projectiles were thrown at officers, with a number of injured and hospitalized, she said.

"This is unacceptable. Police attended the incident in Wakeley last night to assist that community in response to calls for assistance, and the crowd turned on police," Webb said.

The attack came two days after six people were killed and dozens injured in a stabbing at a Sydney shopping centre. Police said that the attack was carried out by a man suffering poor mental health and was not thought to be terror-related.