Religious leaders are joining together in prayer as a hostage incident in Sydney unfolds, and are urging their followers to do the same.

Churches, synagogues and mosques across the country will be open tonight for prayer services, and a multi-faith vigil is being held in Lakemba Mosque in Sydney today.

President of the Lebanese Muslim Association, Samier Dandan, told the BBC: "The vigil crossed many different religious groups - Muslims, Catholics, Protestants, Jewish communities... This is a showcase and demonstration that the community can come together in solidarity and work together as a family to try to address whatever issue that we face collectively."

A statement signed by over 40 Muslim institutes, groups and associations was released today condemning the incident.

"The Australian Muslim community shares with fellow Sydneysiders their utter shock and horror at the unprecedented scenes emerging from the Lindt café in Martin Place this morning. Our immediate thoughts go to the hostages and their loved ones. We pray for their safety and hope this matter is resolved quickly and peacefully," the statement reads.

It continues: "We reject any attempt to take the innocent life of any human being, or to instil fear and terror into their hearts. Any such despicable act only serves to play into the agendas of those who seek to destroy the goodwill of the people of Australia and to further damage, and ridicule the religion of Islam, and Australian Muslims throughout the country."

The statement issues a reminder that the Arabic inscription on the flag displayed in the café "is not representative of a political statement, but reaffirms a testimony of faith that has been misappropriated by misguided individuals that represent no one by themselves".

The Muslim groups call on "all Australians to stand together and support each other" as the events unfold.

"We pray for a swift resolution to this crisis with no injuries or loss of life," they conclude.

The Archbishop of Sydney tweeted this morning asking for prayer for all those involved in the incident, and for a peaceful resolution. The hashtag #PrayForSyndey is currently trending in Australia.

World leaders have also been quick to express their solidarity, including Indian and Canadian Prime Ministers Narendra Modi and Stephen Harper:

Australian police locked down the centre of Sydney today after an armed assailant took a number of hostages in a Lindt café in the heart of the financial district.

The hostages were forced to display an Islamic flag in the window, sparking concerns that the incident is linked to extremist group Islamic State. However, the flag is not the same one as used by ISIS, but instead bears a general expression of Islamic faith in Arabic: "There is no god but Allah; Muhammad is the Messenger of Allah."

Five hostages have so far either escaped or been released, and police, snipers and a SWAT team are surrounding the café while helicopters fly overhead.

Police Commissioner Andrew Scipione told a news conference: "Our only goal is to get those people who are currently caught in that building out of there safely. Nothing will change."

"If people are being contacted by hostages, we would ask that they ensure that the gunman inside speaks to our trained negotiators. They are the people that can help in this situation," he added.

"I understand that no one has been injured, and if that is true we are grateful."