The US is reducing the number of personnel at its Al-Udeid air base in Qatar, according to the BBC's US partner CBS News, which officials have called a "precautionary measure".

A statement by the Qatar government said the step was being taken "in response to the current regional tensions".

This comes after US President Donald Trump said the US would take "very strong action" against Iran if the authorities execute anti-government protesters. Iran says it will retaliate if attacked by the US.

According to rights groups, more than 2,400 anti-government demonstrators have been killed in the recent violent crackdown by the Iranian authorities.

The Qatar government said that it would continue to "implement all necessary measures to safeguard the security and safety of its citizens and residents as a top priority, including actions related to the protection of critical infrastructure and military facilities".

Iran launched a missile attack on the Al-Udeid air base in June in what it said was retaliation for US strikes against its nuclear sites.

The 24-hectare (59-acre) Al-Udeid air base in the desert outside the Qatari capital Doha is the largest US military base in the Middle East.

It is also home to the US military's headquarters for all air operations in the region, housing about 10,000 personnel. Some UK military personnel also serve there on rotation.

Citing diplomats, the Reuters news agency reported that while some personnel had been told to leave the base, there was no immediate sign of large numbers of troops being bussed out like in the hours before the Iranian strike last year.

A senior adviser to Iran's Supreme Leader Ayatollah Ali Khamenei warned Donald Trump on Wednesday that the June attack had demonstrated Iran's ability to respond to any attack.

"It would certainly help create a real understanding of Iran's will and capability to respond to any attack," Ali Shamkhani wrote in a post on X.

The US Mission to Saudi Arabia also on Wednesday advised its personnel and citizens to "exercise increased caution and limit non-essential travel to any military installations in the region".

The US has been threatening to intervene in Iran over the killing of protesters. On Tuesday, Trump wrote on his Truth Social platform that Iranian authorities would "pay a big price" for the killings, and urged people to "keep protesting".

He has also said that Iranian leaders had called him and that "they want to negotiate" but that the US "may have to act before a meeting".

Iran's government has accused the US of seeking to "manufacture a pretext for military intervention", with the parliament speaker warning that if the US attacked, both Israeli and US military and shipping centres in the region would become legitimate targets.

The latest protests in Iran began at the end of December following the collapse of the currency and as the country deals with soaring living costs.

They quickly widened into demands for political change and became one of the most serious challenges to the clerical establishment since the 1979 Islamic revolution.

The US-based Human Rights Activists News Agency (HRANA) said it had so far confirmed the killing of 2,403 protesters, as well as 12 children, despite an internet blackout. More than 18,434 protesters have been arrested during the unrest, the group also reported.