POLITICAL MOTIVATION SUSPECTED

Speaking with the media outside the Parliament House Monday afternoon, Prime Minister Abbott said the hostage drama could be politically motivated, and that he could think of "almost nothing more distressing or terrifying" than being caught up in the siege.

It was a "disturbing incident" and the NSW police, Federal Police and the government were currently investigating the motivation, he said.

"We have to appreciate that even in a society such as ours, there are people who would wish to do us harm," Abbott said.

"That's why we have police and security organizations of the utmost professionalism that are ready and able to respond to a whole range of situations and contingencies including this situation that we are now seeing in Sydney," he added.

"The whole point of politically motivated violence is to scare people out of being themselves. Australia is a peaceful, open and generous society. Nothing should ever change that and that's why I would urge all Australians today to go about their business as usual," said Abbott.

The Australian Federal Government has convened a meeting of the National Security Committee this morning. It has been warning for months that a terror attack in Australia could happen.

In Canberra, a Xinhua reporter has witnessed heightened security at the Federal Parliament, with a heavily armed police standing guard at the gate and two police patrolling around.

Meanwhile, Daniel Andrews, Premier of the State of Victoria, said the state has been on high alert following the hostage incident in Sydney, and called on the communities to report any suspicious activity to police.

INTERNATIONAL WARNING

The Chinese Embassy and Chinese Consulate in Australia on Monday issued an emergency alert aimed at protecting Chinese citizens living in Sydney, warning them to stay away from the hostage crisis.

"We have been in close contact with the Australian federal government in order to understand the situation, especially to find out if there were any Chinese citizens held hostage," the office said in a statement.

In parallel, New Zealand Prime Minister John Key contacted Australian Prime Minister Abbott on Monday to offer a message of support over the Sydney hostage situation.

Authorities in New Zealand have been in close touch with Australian counterparts in monitoring the crisis, Key said.

"Our hearts go out to those involved and our thoughts are very much with them and their families," Key said in a statement.

In Washington, the White House has confirmed that U.S. President Barack Obama has been briefed on the ongoing situation in Sydney, while the U.S. Consulate has released a statement regarding American citizens in Australia.

"U.S. citizens are strongly encouraged to review your personal security plan, remain aware of your surroundings including local events and monitor local news stations for updates," said the statement.

In New Delhi, Indian Prime Minister Narendra Modi Monday branded the hostage crisis as "inhuman" and said he was praying for victims' safety.

"The incident in Sydney is disturbing. Such acts are inhuman and deeply unfortunate. I pray for everyone's safety," Modi tweeted.

Indian External Affairs Minister Sushma Swaraj spoke with the Indian consul general in Sydney to seek details of the incident, while the Indian consulate there has been evacuated for precaution.