The US and Israel are continuing to hit Iran after the death of Supreme Leader Ayatollah Ali Khamenei, leading the UK government to advise against travelling to 21 countries in the Middle East.

Places previously considered safe, such as Dubai and Doha, have now become the target sites of retaliatory strikes from Iran.

Airlines have cancelled flights to Dubai and other destinations due to the conflicts.

Emirates, which operates flights from London Stansted to Dubai, released a statement to passengers last week.

It read: "Due to multiple regional airspace closures, Emirates has temporarily suspended operations to and from Dubai.

"Emirates urges customers to check their flight status on emirates.com for the latest updates before proceeding to the airport.

"We are actively monitoring the situation and engaging with relevant authorities.

"The safety and security of our passengers and crew remain our highest priority."

Flights due to depart Stansted for Dubai have been cancelled today.

READ MORE: Stansted Airport

A black plume of smoke rises from a warehouse in the industrial area of Sharjah City in the United Arab Emirates, following reports of Iranian strikes in Dubai, United Arab Emirates (Image: AP)

The Foreign, Commonwealth and Development Office (FCDO) advises against all travel to the following countries:

Meanwhile, "no travel is considered safe" to Oman or Turkmenistan.

British nationals currently in Bahrain, Israel, Kuwait, Palestine, Qatar, and the United Arab Emirates have been advised to register their presence in the country to receive direct updates from the FCDO.

The FCDO advises against all but essential travel to the following countries:

The FCDO further advised British nationals in the affected areas to follow the advice of the regional authorities, ensure travel documents are up to date and to stay away from military facilities.

© Eastern Daily Press