NEW DELHI: At least one gunman is holding staff and customers hostage at Lindt Cafe in the central business district of Sydney, Australia. At the time of writing, five hostages were seen escaping the cafe, which if heavily surrounded by armed police. It is unknown how many hostages remain inside.

The reason for the attack also remains unknown, although Prime Minister Tony Abbott said that it could be “politically motivated.” According to reports, a black Islamic flag is displayed at the window of the besieged cafe.

Police, in the meanwhile, said that they have made contact with the gunman. Six hours into the siege, three people were seen escaping from the building housing the cafe. An hour later, two other people followed. The reason for their release or escape, also remains unknown.

“The information I have is that nobody has been harmed or injured at this moment,” the New South Wales deputy police commissioner Catherine Burn has been quoted as saying.

The incident began when a man carrying blue sports bag entered the cafe Monday morning at about 9:45 am. Early images showed hostages forced to hold a black flag against the window. The flag bears the Islamic creed, raising suspicion that the attack was a terrorist attack. According to reports, the flag appears to bear the Shahada, an Islamic affirmation of the oneness of God that reads: “There is no god but the God, Muhammad is the messenger of God.”

The creed is commonly used and appears on the Saudi Arabian flag, for instance, and has been adopted by Islamist groups such as Jabhat al-Nusra and Hizb ut-Tahrir.

PM Abbott, however, has urged caution. “We don’t yet know the motivation of the perpetrator, we don’t know whether this is politically motivated although obviously there are some indications that it could be,” the prime minister said.”

““We have to appreciate that even in a society such as ours, there are people who would wish to do us harm, that’s why we have police and security organisations 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,” Abbott said.

“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,” the Prime Minister continued.

Although the motive behind the attack and its link to any organised outfit remain unknown, leading Islamic figures have issued condemnations. Australia’s grand mufti, Dr Ibrahim Abu Mohammad, said he was “devastated” by the news. “The grand mufti and the Australian National Imam Council condemn this criminal act unequivocally and reiterate that such actions are denounced in part and in whole in Islam… We, along with the wide Australian society, await the results of the investigation about the identity of the perpetrators and their underlying motivations behind this criminal act,” a statement said.

Meanwhile, #SydneySiege began trending on Twitter, with support pouring in for the hostages.

Users also took to social media to draw a distinction between religion and the attack.

Meanwhile, Indian PM Narendra Modi, referring to the crisis, said, “Such acts are inhuman and deeply unfortunate. I pray for everyone's safety.”

The Indian consulate in Sydney, located about 300 metres from the cafe, has been evacuated. External Affairs Minister Sushma Swaraj reportedly spoke with Indian High Commissioner Biren Nanda to seek details on the incident.

MEA spokesperson Syed Akbaruddin provided a number for queries on Indian nationals following the incident, although whether any Indians are held hostage inside the cafe remains unknown.

Following the incident, security for Indian cricketers -- currently in Brisbane -- has been strengthened. "We are constantly in touch with Cricket Australia top bosses. We are monitoring the situation closely and security of our players is paramount. The players are in Brisbane and everything is normal there," said BCCI Secretary Sanjay Patel.

The United States also evacuated its consulate and issued a statement to its citizens to "maintain a high level of vigilance and take appropriate steps to enhance your personal security".