Sydney Hostage Crisis in Pictures

A lone gunman took an as yet unknown number of people hostage at the Lindt Chocolat Cafe in Sydney, Australia.

Above: Armed policeman are seen outside Lindt Cafe on Philip St, Martin Place. Sydney, December 15, 2014.

Police moved in to cordon off the area.

Above: Police secure the scene near the Lindt Cafe, Martin Place on December 15, 2014 in Sydney, Australia.

TV cameras aimed at the cafe's windows showed several people with their hands pressed against the glass.

Above: People wit their hands up inside the Lindt cafe in Sydney, Australia. Monday, December 15, 2014.

At least 10 hostages have managed to escape from the cafe.

Above: A hostage runs towards a police officer outside the Lindt cafe, where other hostages are being held, in Martin Place in central Sydney December 15, 2014.

NSW Police Force Deputy Commissioner Catherine Burn told reporters that the police are seeking to resolve the situation "peacefully".

Above: Catherine Burn, Deputy Commissioner of the Specialist Operations speaks to the media about the Sydney hostage incident at Sydney Police Centre on December 15, 2014 in Sydney, Australia.

The cafe is located in Martin Place, a plaza in the heart of Sydney's financial and shopping district.

Above: Police secure the area near the Lindt Chocolate Café in Martin Place on December 15, 2014 in Sydney, Australia.

Major landmarks in Sydney, including the Sydney Opera House, have also been evacuated due events possibly related to the hostage crisis.

Above: Armed police are seen outside the Lindt Cafe, Martin Place on December 15, 2014 in Sydney, Australia.

The attack occurred during Monday morning at rush hour.

Above: Police discuss the situation on Philip St near the Lindt Cafe, Martin Place on December 15, 2014 in Sydney, Australia.

A black flag with white Arabic writing reading "There is no God but Allah" and "Mohammed is the messenger of God" was seen inside the cafe.

Above: Ladies rush through Philip St past armed police officers at the Lindt Cafe, Martin Place on December 15, 2014 in Sydney, Australia.

While Sydney airspace remains open, several flights were diverted to avoid the central business district.

Above: Armed police are seen outside the Lindt Cafe, Martin Place on December 15, 2014 in Sydney, Australia.

"All Australians should be reassured that our law enforcement and security agencies are well trained and equipped and are responding in a thorough and professional manner," Tony Abbott said.

Above: Australian Prime Minister Tony Abbott briefs the press on the government's response to the siege at the Lindt Chocolate Café in Martin Place, Sydney, on December 15, 2014 in Canberra, Australia.