A van loaded with gas canisters has rammed into the Australian Christian Lobby office in Canberra and exploded.

No one inside the building is thought to be injured but the driver is reportedly receiving medical attention. His motive is unknown at this time and it has not been declared an act of terrorism.

Lobby director Lyle Shelton tweeted a photograph of the aftermath, saying: "A vehicle has rammed our office in Canberra & exploded all staff are safe," he posted. "I do not know the condition of the driver. Prayers appreciated."

The white van struck the Eternity House building at around 10.45pm local time (11.45am GMT) . The explosion destroyed the vehicle and shattered some of the windows of building. The car was a smouldering wreck when emergency services arrived at the scene. Shelton posted a second photo showing the destruction in detail.

A police spokesman said they were investigating a vehicle fire at the Australian Christian Lobby. "No one was injured inside the building. There are no public safety issues and ACT are seeking any witnesses to the incident."

Mr Shelton told the Australian Daily Telegraph: "We have had the normal trolls on social media and even had death threats sent to our Canberra office over the year but I am very concerned someone would do this.

"It is a relief the building was unoccupied at the time and we are all very thankful our staff are all safe. Obviously this is very unsettling to us but also to anyone in Australia, for this to happen in Canberra, our nation's capital is very disappointing. It is something I thought would never happen here, I can't believe it."