Beirut explosion: Rescuers flown to epicentre as survivors pulled from rubble, death toll up to 135

International rescue teams are being flown to Beirut to help pull survivors from mountains of rubble caused by an explosion so large, it would have gutted half of the Sydney region.

At least 135 people have died after yesterday's horrific blast that tore through the Lebanese capital and shredded buildings so badly that they now look as if they are under construction.

READ MORE: Before-and-after images of Beirut explosion show devastation

A giant 2700-tonne stockpile of volatile ammonium nitrate stored dockside – and just 100 metres from homes - in Beirut for the last six years is believed to be the cause of the huge explosion.

The explosion was felt 190 kilometers from Beirut and caused damage as far as ten kilometers from the blast site.

To give perspective of the sheer power of the explosion, if it had blown up in Sydney's CBD it would've shattered windows as far as Strathfield – with the damage zone even sprawling to Manly and south past Sydney Airport.

All over the city today rescue workers scrambled to dig through the wreckage in the hope of finding people alive after they'd been buried by building pancaked into the ground.

Isam Ata told 9News he was trapped under rubble for 16 hours and was later hooked up to an oxygen tank as workers rushed to free his leg.

READ MORE: Shocking video shows moment bride's wedding was destroyed

In another location, the faint voice of a little girl under a huge pile of rubble was heard, with rescuers using their bare hands and a torchlight to pull her to safety.

Omar Jheir from Parramatta told 9News his home was just 500 metres from the explosion's ground zero, but it was completely destroyed, along with his café and hotel, in the shockwave.

Shaya Laughlin, from the Gold Coast, says she was closing her apartment window when the blast hit and threw her across the room.

An estimated 300,000 structures have been damaged by the explosion, including the Australian embassy which had its windows blown out.

Images of the port before and after the devastating blast show the full extent of the damages, including massive chunks of concrete that were thrown through the air.

READ MORE: Heartbreaking video shows woman play piano amid Beirut rubble

Several port officers have tonight been put into house arrest as authorities working to determine the exact cause of the blast also look to see who might have been responsible.

Powerful aerial footage show the full extent of the damage, with the scene more like a war zone: deep craters across the ground, the rubble of destroyed buildings and smoke rising across the city.

Beirut Governor Marwan Abboud told Saudi-owned TV station Al-Hadath that nearly 3000 people are homeless and losses from the blast are estimated to be up to $20 billion (US$15 billion).

"Beirut as we know it is gone and people won't be able to rebuild their lives," said Amy, a woman who swept glass from a small alley beside by a tall building.

"This is hell. How are they (people) going to survive. What are they going to do?" she said, blaming officials for lack of responsibility and "stupidity."

Hospitals were overwhelmed by the injured. One that was damaged in the blast had to evacuate all its patients to a nearby field for treatment.

It was the worst single explosion to strike Lebanon, a country whose history is filled with destruction — from a 1975-1990 civil war, conflicts with Israel and periodic terrorist attacks.