Five people escaped from a Sydney cafe where a gunman took an unknown number of hostages during Monday morning rush hour. Two people inside the cafe earlier held up a flag with an Islamic declaration of faith that has often been used by extremists, raising fears that a terrorist incident was playing out in the heart of Australia’s biggest city.

The first three people ran out of the Lindt Chocolat Cafe in downtown Sydney six hours into the hostage crisis, and two women sprinted from a fire exit into the arms of waiting police shortly afterward. Both women were wearing aprons with the Lindt chocolate logo, indicating they were cafe employees.

As the siege entered its 12th hour Monday night, basic questions remained unanswered. Police refused to say how many hostages were inside the cafe, what they believed the gunman’s motives might be, whether he had made any demands or whether the hostages who fled the cafe escaped or were released.

“I would like to give you as much as I can but right now that is as much as I can,” New South Wales state police Commissioner Andrew Scipione said. “First and foremost, we have to make sure we do nothing that could in any way jeopardize those still in the building.”

Police were negotiating with the gunman and said they had no information to suggest anyone had been hurt. Scipione said they had not confirmed whether the siege was related to terrorism.

“Our only goal tonight and for as long as this takes is to get those people that are currently caught in that building out of there safely,” he said.

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.

The drama began around 9:45 a.m. in Martin Place, a plaza in the heart of the city’s financial and shopping district that is packed with holiday shoppers this time of year. Many of those inside the cafe would have been taken hostage as they stopped in for their morning coffees.

Television video shot through the cafe’s windows showed several people with their arms in the air and hands pressed against the glass, and two people holding up a black flag with the Shahada, or Islamic declaration of faith, written on it.

The Shahada translates as “There is no god but God and Muhammad is his messenger.” It is considered the first of Islam’s five pillars of faith, and is similar to the Lord’s Prayer in Christianity. It is pervasive throughout Islamic culture, including the green flag of Saudi Arabia. Jihadis have used the Shahada in their own black flag.

A number of Australian Muslim groups condemned the hostage-taking in a joint statement and said the flag’s inscription was a “testimony of faith that has been misappropriated by misguided individuals.”

In a show of solidarity, many Australians offered on Twitter to accompany people dressed in Muslim clothes who were afraid of a backlash from the cafe siege. The hashtag #IllRideWithYou was used more than 90,000 times by late Monday evening.

Seven Network television news staff watched the gunman and hostages for hours from a fourth floor window of their Sydney offices, opposite the cafe.

The gunman could be seen pacing back and forth past the cafe’s windows. Reporter Chris Reason said the man carried what appeared to be a pump-action shotgun, was unshaven and wore a white shirt and a black cap.

Earlier in the day, network staff counted about 15 different faces among hostages forced up against the windows.

“The gunman seems to be sort of rotating these people through these positions on the windows with their hands and faces up against the glass,” Reason said in a report from the vantage point. “One woman we’ve counted was there for at least two hours ? an extraordinary, agonizing time for her surely having to stand on her feet for that long.”

“When we saw that rush of escapees, we could see from up here in this vantage point the gunman got extremely agitated as he realized those five had got out. He started screaming orders at the people, the hostages who remain behind,” he added.

Reason later reported that staff brought plates of food from a kitchen at the rear of the cafe and the hostages were fed.

As night set in, the lights inside the cafe were switched off. Armed police guarding the area outside fitted their helmets with green-glowing night goggles.

St. Vincent’s hospital spokesman David Faktor said a male hostage was in satisfactory condition in the hospital’s emergency department. He was the only one of the freed hostages to be taken to a hospital, and Scipione said he was being treated for a pre-existing condition.

Hundreds of police blanketed the city, streets were closed and offices evacuated. The public was told to stay away from Martin Place, site of the state premier’s office, the Reserve Bank of Australia, and the headquarters of two of the nation’s largest banks. The state parliament house is a few blocks away.

Workers in the cordoned-off area were asked to stay home Tuesday, indicating police believe the hostage drama could stretch into the next day.

“This is a very disturbing incident,” Prime Minister Tony Abbott said. “It is profoundly shocking that innocent people should be held hostage by an armed person claiming political motivation.”

Lindt Australia posted a message on its Facebook page thanking the public for its support.

“We are deeply concerned over this serious incident and our thoughts and prayers are with the staff and customers involved and all their friends and families,” the company wrote.

Infosys, India’s second-largest IT services provider, confirmed that one of its employees was among the hostages. The staffer’s family has been informed, it said.

Australia’s government raised the country’s terror warning level in September in response to the domestic threat posed by supporters of the Islamic State group. 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 Islamic State leader in Syria to behead a random person in downtown Sydney.

The Islamic State group, which now holds a third of Syria and Iraq, has threatened Australia in the past. In September, Islamic State group spokesman Abu Mohammed al-Adnani issued an audio message urging so-called “lone wolf” attacks abroad, specifically mentioning Australia. Al-Adnani told Muslims to kill all “disbelievers,” whether they be civilians or soldiers.

One terrorism expert said the situation appeared to be that of a “lone wolf” making his own demands, rather than an attack orchestrated by a foreign jihadist group.

“There haven’t been statements from overseas linking this to extremist groups outside the country ? that is quite positive,” said Charles Knight, lecturer in the Department of Policing, Intelligence and Counter Terrorism at Australia’s Macquarie University. “The individual or individuals involved didn’t kill early, which is part of the pattern of some recent international attacks. … It seems to be shifting more into the model of a traditional hostage situation, rather than the sort of brutal attacks we’ve seen overseas.”

(AP)