US SENATOR Jeff Flake rejected accusations of “sonic attacks” against Washington’s diplomats in Cuba on his latest visit there on Saturday.

Republican Mr Flake said there was no evidence that the mysterious ear-piercing noise that embassy staff claimed made them ill and prompted October’s downgrade in diplomatic relations was a malicious attack.

The Senate foreign relations committee member, an advocate of detente with Cuba, said classified briefings from US officials had left him with no reason to doubt the Cuban account, without revealing their contents.

On Friday, Mr Flake met Cuban Foreign Minister Bruno Rodriguez and officials from the Interior Ministry, which oversees domestic security and works with foreign police agencies.

They told him four visits to Havana by investigating FBI agents had found no evidence that the illnesses suffered by 24 embassy staff and their spouses at their homes and hotels was caused by attacks.

“The Cuban Interior Ministry is saying the FBI has told them there is no evidence of a sonic attack, even though that term is being used, ‘attack,’ there is no evidence of it,” Mr Flake told the Associated Press news agency.

“There’s no evidence that somebody purposefully tried to harm somebody,” he added.

“Nobody is saying that these people didn’t experience some event,” Mr Flake stressed, “but there’s no evidence that that was a deliberate attack by somebody — either the Cubans or anybody else.”

“As I said, I won’t talk about what I have seen in a classified setting, but nothing is inconsistent with what the Cubans have said and I think the FBI would say that.”

Following the claims, the US State Department withdrew most of its embassy staff in October over alleged health concerns and expelled 15 Cuban diplomats from Washington, ostensibly to ensure “equity.”

Secretary of State Rex Tillerson has said he is “convinced these were targeted attacks” but the US does not know who was behind them.

It partially reversed gains made in the December 2014 detente between Cuba and the US under former president Barack Obama which led to re-establishment of full diplomatic relations in August 2015 after a 54-year hiatus.

Mr Flake is the main sponsor of a Senate Bill to abolish travel restrictions on US citizens wishing to visit Cuba, supported by a cross-bench majority of 54.