Emergency services have been called to a restaurant in Salisbury in the UK after two people were taken ill.

Wiltshire Police said the area surrounding Prezzo restaurant has been closed while they work to establish what caused the "medical incident" involving a man and a woman.

The ambulance service alerted detectives at about 6.45pm. Firefighters were also in attendance.

One witness said he saw a person in a hazardous material suit go between the restaurant and the ambulance.

"Police were called by the ambulance service to Prezzo, High Street, Salisbury at 6.45 pm today following a medical incident involving two people - a man and a woman," Wiltshire Police said in a statement.

"As a precautionary measure, the restaurant and surrounding roads have been cordoned off while officers attend the scene and establish the circumstances surrounding what led them to become ill."

South Western Ambulance Service said medics were first called at 5.38pm.

The patients were conscious at the last update and were being treated at the scene, a spokeswoman added.

Tensions are heightened in the cathedral city because of recent Novichok poisonings.

The Italian restaurant is a short walk from Queen Elizabeth Gardens, which was until recently closed off after 44-year-old Dawn Sturgess was fatally poisoned by the nerve agent.

Police said she was killed by the same chemical used in an alleged hit by Russian military intelligence officers on former spy Sergei Skripal. 

Kremlin says Skripal poisoning suspects have nothing to do with Putin

The two suspects in the poisoning of former spy Sergei Skripal have nothing to do with Russian President Vladimir Putin or the government, a Kremlin spokesman has told Russia media.

Britain has charged two Russian men, identified as Alexander Petrov and Ruslan Boshirov, with attempting to murder Mr Skripal and his daughter Yulia by spraying a chemical weapon on Mr Skripal's front door in the southern English city of Salisbury in March.

"The fact is that neither Petrov nor Boshirov have nothing to do with Putin, and the Kremlin of course," Dmitry Peskov was quoted as saying on Russia’s Interfax news agency.

Mr Putin said on Wednesday that the two men were civilians and that there was "nothing special and criminal" about them.

The duo appeared on Russia's state-funded RT television station on Thursday, insisting they were innocent tourists who had flown to London for fun and visited the city of Salisbury to see its cathedral.

Britain has said the two men were Russian military intelligence officers almost certainly acting on orders from high up in the Russian state.

Russia has vehemently denied any involvement in the incidents.

Mr Skripal and his daughter were found slumped unconscious on a bench in Salisbury in March.

They spent weeks in hospital before being discharged.