British tourists have been warned to expect cancelled flights and longer plane journeys following the “biggest single disruption to air travel since 9/11”.

The delay come after Iran launched 300 missiles and drones at Israel in response to the Jewish state allegedly attacking its consulate in the Syrian capital Damascus.

On Sunday, Israel had shut its airspace following the attack, along with Lebanon and Iraq although it has since reopened.

Iran‘s airspace is used by airlines travelling between Europe and Asia, with many choosing to redirect flights to avoid the airspace. This means airlines will instead have to travel through Turkey or Egypt instead.

Mark Zee, founder of OPSGROUP, which monitors airspace and airports, said it was the biggest single disruption to air travel since the attack on the World Trade Centre on September 11, 2001.

He told Reuters: “Not since then have we had a situation with that many different air spaces closed down in that quick succession, and that creates chaos.”

He warned the disruptions are expected to last for the next couple of days. The cancellations mainly impacted travellers to and from Israel and Jordan over the weekend, with airlines such as Etihad, Emirates, and Qatar Airways cancelling flights.

Although many flights have resumed today, passengers are advised to anticipate some delays. However, British travellers won’t just be affected by flight cancellations.

Several airlines are also adjusting their flight paths to steer clear of Iranian airspace. Consequently, flights will take longer, particularly on UK-Asia routes.

An easyJet spokesperson told The Sun: “Due to the evolving situation in Israel, easyJet has taken the decision to temporarily pause operations to and from Tel Aviv until 21 April.

“Customers on affected flights have been contacted directly via SMS and email via the details provided at the time of booking. The safety and security of our passengers and crew is always easyJet’s highest priority.”

Wizz Air is to resume flights tomorrow to Tel Aviv but warns passengers to expect “some schedule changes”. Ryanair said planes to resume flights to Tel Aviv in June.

British Airways resumed flights to Israel earlier this month, albeit with a Cyprus stopover to avoid staff staying in Tel Aviv.

Virgin Atlantic confirmed it won’t return to Israel until September, although said they are “not currently flying over Iranian airspace”.

The UK Foreign Office has also updated it’s travel advice for anyone heading to Israel. Areas near Gaza, the West Bank and northern Israel are advised against all travel, while the rest of the country is advised against unless essential.

KLM – flights to and from Tel Aviv cancelled until tomorrow

Air Canada – flights to and from Tel Aviv cancelled until tomorrow

EasyJet – flights to and from Tel Aviv cancelled until April 21

Iberia Express – flights to and from Tel Aviv cancelled today

Wizz Air – flights to and from Tel Aviv cancelled until tomorrow

Lufthansa – flights to and from Tel Aviv cancelled until Thursday

Qantas – flights between London and Perth rerouted, with new stopover in Singapore

Finnair – flights rerouted over Egypt rather than Iran, with flights to Doha taking longer

Some airlines are yet to resume flights to Tel Aviv.