The SAS hero was reportedly pictured evacuating civilians.

A member of the British Army’s Special Air Service (SAS) has been termed as a hero after storming into DusitD2 hotel alongside elite units to save hostages and take on gunmen during a terror attack.

The serving member of the elite unit was reportedly on a training mission with Kenyan Special Forces when the attack was launched.

At least four terrorists were involved in the slaughter at the 14 Riverside Drive office complex in Nairobi.

The attack killed 21, including British man Luke Potter and an American woman, while another Brit is amongst the wounded.

The soldier is said to have taken part in the rescue mission with US Navy Seals.

Pictures and video from the scene show the Special Forces hero in jeans and body armour, holding a gun, as he escorts bystanders to safety.

The weapon he is clutching is a Diemaco C8 Carbine - standard issue for Special Forces soldiers.

A source told The Sun: "UK Special Forces always run towards the sound of gunfire.

"During the operation he fired off some rounds- it’s safe bet he hit his target- the SAS don’t miss.

"He is a long serving member of the Regiment, there is no doubt his actions saved lives."

Chilling CCTV earlier showed four terrorists armed with guns and grenades during the attack on the DusitD2 hotel.

The Riverside complex that housed the hotel is also the location of the offices of a number of international businesses.

One of the victims was said to be an employee of LG Electronics.

Other firms based there include Colgate Palmolive, Reckitt Benckiser, Pernod Ricard, Dow Chemical and SAP.

The attack started the afternoon of January 15 came to an end overnight, with all of the militants reportedly killed.

Islamist group al-Shabaab, which has links to al-Qaeda, later said it was behind the killings.