The United Nations has warned that freedom of expression is under threat in many countries across the Middle East due to the war.

Volker Türk, the UN human rights chief, reported on Wednesday that around 3,000 people have been arrested since the start of the war.

Across the region, governments are tightening security measures and severely restricting freedom of speech and assembly, the UN official said.

The war began at the end of February with Israeli and US attacks on Iran. Since then, not only Israel but also various Gulf states have become targets of Iranian retaliatory strikes.

The UN Human Rights Office in Geneva estimates that 2,345 people have been arrested in Iran since the start of the war on charges "related to national security, including terrorism, dissent, alleged espionage and cooperation with the enemy."

Türk also referred to official Israeli figures, according to which 200 Palestinians were arrested in the first week of the war, including on charges of alleged "incitement" and "glorification of the enemy."

The UN Human Rights Office reported dozens of summary trials in the United Arab Emirates for the dissemination of videos showing strikes and defensive missiles.

In the UAE and Qatar, 109 and 313 people respectively were arrested for filming or sharing information.

Arrests were also reported in Bahrain for videos or posts on social media. According to Türk, one activist has died in custody.

In Israel, the military censorship authority is attempting to restrict press freedom, Türk said.

He also referred to a threat by the head of the US Federal Communications Commission (FCC) to revoke broadcasting licences due to reporting that is critical of the war.

Media freedom was all the more important in wartime, Türk said. "The exercise of such rights must be protected, not threatened."