Kenya’s president says security forces have killed all four militants who stormed an upscale hotel complex in Nairobi in an attack that killed at least 14 people.

Uhuru Kenyatta said 14 civilians were confirmed dead and more than 700 others had been safely evacuated.

Police said the attack on the DusitD2 hotel began shortly after 3pm local time on Tuesday (11pm Tuesday, AEDST) with an explosion in the car park and then a suicide bomb blast in the foyer, police said.

Somali militant Islamist group al Shabaab claimed responsibility for the attack.

Security officers search for attackers in the upmarket hotel complex. Photo: EPA/AAP

At least two groups of people had still been trapped inside as dawn broke, and gunfire continued to ring out around the complex in Riverside Drive.

An earlier estimate put the death toll at 15.

Eleven Kenyans, an American and a Briton were among the casualties, morgue staff said. Two victims had not been identified.

A woman is treated for her injuries after being rescued from the Dusit Hotel complex. Photo: Getty

No Australians are believed to have been injured in the attack, but consular officials are making urgent inquiries with local authorities to determine whether any Australians were affected.

“At this time, we are not aware of any Australians being affected,” a spokesperson for the Department of Foreign Affairs told AAP.

It is understood all staff at the Australian High Commission, which is situated across the road from the compound, are safe.

A woman reacts after being rescued from the Dusit Hotel. Photo: Getty

Blasts and shots had punctuated the night, undercutting assurances from the interior minister late on Tuesday that the scene had been secured and complicating the rescue of scores trapped inside.

Some of those trapped got messages out begging for medical help.

Army troops arrive to restore calm in Nairobi on Wednesday. Photo: AFP/Getty

The first responder told Reuters that at least two groups of people remained in the hotel and business complex just before 7am on Wednesday.

Families who went to the Chiromo morgue seeking loved ones were told they could not view the bodies until a forensic investigation had been performed, provoking grief and anger.

One man who only gave his name as David said he was yet to hear from a relative in the hotel complex.

The family of a missing 35-year-old man collapsed in the courtyard upon hearing that a body had arrived with his identification papers.

“He is gone. He is gone,” the father repeated into his phone as his mother wrapped a shawl around herself and wept.

Another family arrived, demanding to see whether their relative was there but were told only police had access.

Outside the morgue, two Red Cross ambulances waited, their drivers asleep inside. They would go to the complex to retrieve casualties once it was safe, morgue staff said.

Kenya has seen a number of terror attacks in recent years – most notably in areas close to the Somali border and in the country’s capital.

Al Shabaab killed 67 people at the Westgate shopping centre in 2013 and nearly 150 students at Garissa university in 2015.