Hostages being held by a gunman in a Sydney cafe have been freed following a police operation.

Gunfire and explosions were heard as the police moved in to end the hostage crisis that had stretched for 16 hours. Three people, including the hostage-taker were killed, police said. A police officer was also injured but was in a stable condition.

Andrew  Scipione,  New South Wales (NSW) police commissioner, commended the work of his department. He said there had been 17 hostages in total.

Television images showed hostages streaming out of the Lindt Chocolate cafe. Some were taken out in stretches as ambulance sirens wailed.

The hostage crisis had begun early on Monday.

Australian media, quoting a police source, identified the hostage-taker as Man Haron Monis, an Iranian refugee with a criminal past.

"This is a very disturbing incident," Tony Abbott, Australia's prime minister, said hours after the hostage crisis started.

Abbott called the siege a "brush with terrorism".

"He had a long history of violent crime, infatuation with extremism and mental instability," the prime minister said. "As the siege unfolded ... he sought to cloak his actions with the symbolism of the ISIL death cult."

Channel 10 news said it received a video in which a hostage inside the cafe had relayed the gunman's demands. The station said police requested they not broadcast it, and Scipione separately asked all media that might be  contacted by the gunman to urge him instead to talk to police.

Hundreds of police flooded into Sydney's business district, streets were closed and offices evacuated.

The public was told to stay away from Martin Place - the area where the Lindt Chocolate Cafe is located.

Terror threats

The hostage crisis came after Australia joined the fight against the Islamic State of Iraq and the Levant (ISIL) group after an appeal by US President Barack Obama several months ago. Australia has deployed a squadron of fighter jets and hundreds of troops to the Middle East.

The Australian government had raised the terror warning level in September in response to the domestic threat posed by supporters of ISIL.

Two weeks later, a known suspect was shot dead by police in Melbourne after he tried to attack police officers with a knife.

Counterterror law enforcement teams later conducted dozens of raids and made several arrests in Australia's three largest cities - Melbourne, Sydney and Brisbane.

One man arrested during a series of raids in Sydney was charged with conspiring with an ISIL leader in Syria to behead a random person in downtown Sydney.

ISIL, which now holds a third of Syria and Iraq, has threatened Australia in the past.

In September, Abu Mohammed al-Adnani, an ISIL spokesperson, issued an audio message urging "lone wolf" attacks abroad, specifically mentioning Australia.
(Al Jazeera)