The US and UK are reducing the number of personnel at the Al-Udeid air base in Qatar, as US President Donald Trump considers whether to take action against Iran over its crackdown on anti-government protests.

Officials have told CBS, the BBC’s US partner, that the partial American withdrawal was a “precautionary measure”. The BBC understands some UK military personnel are also being removed.

A Qatari government statement said the measures reportedly being taken by the US were “in response to the current regional tensions”.

The Foreign Office has also temporarily closed the British embassy in Tehran, which will now operate remotely, a government spokesperson said.

The US embassy in Doha has advised its personnel to exercise increased caution and limit non-essential travel to the Al-Udeid air base.

Iran closed its airspace from 02:45 local time (22:15 GMT) on Thursday to almost all flights, according to the US Federal Aviation Administration’s website.

The closure was initially due to last two hours, but was later extended to 08:00 local time (03:30 GMT), according to the Reuters news agency.

Several airlines have announced they will reroute flights around Iran in response, including Air India and Germany’s Lufthansa.

Air India warned that passengers could experience delays or cancellations as flights through the region were rerouted. Lufthansa issued a statement confirming its flights would avoid Iranian and Iraqi airspace “until further notice”.

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

Regarding the removal of military personnel, the Qatari government said 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”.

A UK Ministry of Defence spokesperson declined to comment on reports that UK personnel were being withdrawn “due to operational security”.

Al-Udeid is the largest US military base in the Middle East and about 10,000 personnel are based there, as well as about 100 UK staff. It is not clear how many will be leaving.

Earlier this week, Trump warned the US would take “very strong action” against Iran if the authorities execute protesters. Iran has said it will retaliate if attacked by the US.

On Wednesday, he said his administration had been told “on good authority” that “the killing in Iran is stopping, and there’s no plan for executions”.

When questioned by a reporter, Trump said that these were “very important sources on the other side” and that he hoped the reports were true.

The US president was also asked whether military action was now off the table, to which he replied: “We’re going to watch and see what the process is.”

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

Speaking to Fox News on Wednesday, Iran’s Foreign Minister Abbas Araghchi warned Donald Trump to “not repeat the same mistake that you did in June,” adding: “You know, if you try a failed experience, you will get the same result.”

The minister also spoke to the reports of a 26-year-old man who had been sentenced to death in Iran, telling the media outlet that “hanging is out of the question” and there would be “no hanging today or tomorrow”.

As well as the temporary closure of the British embassy in Tehran, the US Mission to Saudi Arabia has advised its personnel and citizens to “exercise increased caution and limit non-essential travel to any military installations in the region”.

Italy and Poland have published statements urging their citizens to leave Iran, while Germany has issued a notice to air operators recommending that flights do not enter Tehran, citing potential risk from “escalating conflict and anti-aviation weaponry”.

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.

Amnesty International said there were “mass unlawful killings committed on an unprecedented scale”, citing “verified videos and credible information from eyewitnesses in Iran”.

The organisation urged UN member states to recognise the “crimes committed by security forces” in the protests.