An official from the town of Amatrice - one of the worst affected areas in the Italy earthquake - has told the BBC that three British nationals were among the dead.
Foreign Secretary Boris Johnson said on Thursday that a number of Britons had been "affected" by the earthquake, which has left at least 250 people dead and levelled three small towns after it struck in the early hours of Wednesday.
But the Foreign Office refused to comment on reports of the deaths.
Johnson said extra staff had been sent to the region to help provide support to Britons affected by the "terrible" quake. The Government has offered "any assistance that we can" to the Italian authorities.
He said: "My deepest sympathies are with the Italian people and everyone affected by the terrible earthquake that struck central Italy.
"The British Government has offered any assistance that we can to help with the recovery effort and I have spoken with Italian foreign minister Paolo Gentiloni to express my condolences personally.
"As the scale of the disaster has become clearer we now know that a number of British nationals have been affected.
"British Embassy staff are in the region providing consular support, and we have deployed additional staff to support this effort."
Aftershocks have been felt in central Italy as rescue workers continued efforts to find survivors. At least 365 people were injured in the initial earthquake and the aftermath.
A day after the shallow quake levelled three small towns, a 4.3 magnitude aftershock hit the already-devastated settlement of Amatrice.
Firefighters and rescue crews using sniffer dogs have been working in teams around the hardest-hit areas of the country.
"We will work relentlessly until the last person is found, and make sure no one is trapped," said Lorenzo Botti, a rescue team spokesman.