MORE than 6000 Assyrians marched through the city today in protest against the treament of fellow Christians in Iraq and Syria.

Thoausands packed into Belmore Park from about 10am, where several community leaders made speeches calling on the Australian and other international governments to step in to help those being persecuted overseas.

The protest rally comes as reports emerged of ISIS militants marking Christian homes in Iraq and Syria with a letter 'N', meaning Christian in Arabic. Protest leaders told the crowd Christians were being given three options: to convert to Islam, pay a religious tax or be executed.

media_camera Ramsin and Hera Sefou and their son Luca Sefou, 3, joined the Australian Assyrian community to raise awareness of persecution of Assyrian Christians at the hands of Islamic State fighters in northern Iraq. Picture: John Appleyard

media_camera Chloe Younan and Nineal Hawei, 11, are the school captains of St Hurmzd Assyrian Primary School who spoke to the crowd gathered at Belmore Park. Picture: Craig Greenhill

media_camera The Australian Assyrian community gathered to voice their opposition to the persecution of fellow Christians in Iraq. Picture: John Appleyard

media_camera Police escorted the marchers through the streets from Belmore Park to Martin Place. Picture: John Appleyard

They also told the crowd some were being brutally assaulted and murdered in front of their families.

Thousands of protesters wore T-shirts reading #WeAreN, while chanting "we want peace, we want justice" and "save our Christians".

Many waved placards, some reading "stop genocide against our Christians" and "Stop crimes against humanity".

Among the speakers at the rally were 11-year-olds Chloe Younan and Nineal Hawel, from Saint Hurmizd Assyrian Primary School in Greenfield Park.

media_camera Nineal Hawei and Chloe Younan, both 11, are the school captains of St Hurmzd Assyrian Primary School who spoke to the crowd gathered at Belmore Park. Picture: Craig Greenhill

Chloe told the crowd "bad people do bad things because good people let them".

"We are here to let the people know of the victims of another silent genocide," she said.

"We must ensure justice for those being crushed."

Thousands of protesters then marched down Elizabeth St, through the city to Martin Place, after receiving last-minute approval from the council and police to leave the park.

Police on foot, in cars and motorbikes escorted the large group to Martin Place, blocking traffic for a short time.

media_camera Protestors march into Belmore park at the start of the Australian Assyrian community protest. Picture: John Appleyard

media_camera Mina Hami and Dina Rashleigh joined the Australian Assyrian community which gathered at Belmore Park to raise awareness of persecution of Assyrian Christians. Picture: John Appleyard

media_camera Religious leaders joined the Australian Assyrian community on the march through the streets of Sydney today in protest against the persecution of Christians in Iraq. Picture: Craig Greenhill

media_camera The Sydney Assyrian community march through the streets of Sydney CBD to protest over the murder of fellow Christians in Iraq , Picture Craig Greenhill

media_camera Many of the younger protestors passionately chanted against the persecution of fellow Christians in Iraq. Picture: Craig Greenhill