Horrifying images have emerged of the Tunisia gunman walking along the beach – AK-47 in hand – after killing at least 38 people.

The pictures show the killer calmly moving down the waterline as tourists watch in shock from behind.

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Witnesses say Seifeddine Yacoubi laughed as he heartlessly fired at holidaymakers lounging on the sand.

Sky News reported that the jihadi extremest went into the water and washed, while he concealed his gun in an umbrella.

Tourists look on from behind the gunman who calmly paces the beach. Photo: Sky News

He then emerged from the sea and started to kill tourists indiscriminately.

Reports say he started to move through the resort and then into the town, where workers high up in buildings tried to hit him with bricks and bags of cement.

The shooting lasted 30 to 35 minutes before police killed the gunman.

At least 15 British tourists died in the attack in Sousse, but the country’s Foreign Office said the toll could rise.

The gunman is caught on camera slowly walking through the resort. Photo: Sky News

They said the shooting is “the most significant terrorist attack on British people” since the 2005 London Bombings when 52 people were killed.

It’s been confirmed that three Irish citizens, one Belgian and one German also perished.

The gunman reportedly laughed and joked as he attacked. Photo: AAP

An unknown number of French nationals died.

The gunman, 23, was identified as a university student from the Tunisian town of Gaarfour.

Islamic State claimed responsibility for the attack and referred to the gunman by his jihadi name Abu Yahya al-Qayrawani.

The North African nation, which relies heavily on tourism, announced plans to deploy troops at vulnerable sites and shut dozens of mosques accused of inciting extremism.

Tunisia has been besieged by terrorism since its secular dictator was thrown from office in 2011.

Tunisian Prime Minister Habib Essid said from next month armed guards would be deployed all along the coast and inside hotels.

But Tunisians who rely on tourism fear it will come too late.

“If I were in their shoes, I wouldn’t set foot in Tunisia right now,” said Imed Triki, a shopkeeper in Sousse.

“After this catastrophe, it’s normal that they leave the country so quickly. Do they come here on holiday or to die?”

– with AAP