The number of passengers flying from London Heathrow fell last month, as war in the Middle East weighed on demand for international travel.

About 6.7 million people flew through the airport in April, a 5% drop compared with the same period last year.

The fall reflected the impact from the Iran conflict and “short-term adjustments to travel plans”, the airport said.

However, the number of transfer passengers transiting for onward flights rose 10% in April year-on-year, as travellers rerouting to Asia and Oceania switched to the Heathrow instead of using rival hubs in the Gulf such as Dubai and Doha.

The US-Israeli war on Iran has triggered travel disruption around the world, with flight cancellations, delays and longer journey times.

Meanwhile, fears are rising that the oil crisis resulting from the blockade of Gulf tanker shipping in the strait of Hormuz could lead to fuel shortages this summer and higher ticket prices.

The chief executive of Heathrow, Thomas Woldbye, said travel demand “remains strong” and “current fuel supplies stable”. He added that while passenger numbers in April were weaker compared with the same month in 2025, so far it had been the busiest month at the airport this year.

However, Heathrow said it would review and update its passenger forecast for 2026 next month.

The industry faces growing uncertainty over jet fuel supply, with prices averaging $181 a barrel in the week up to 1 May, according to the International Airport Transport Association, roughly double the average price last year. Prices have risen due to the effective closure of the strait of Hormuz. More than a fifth of the world’s oil normally uses the channel.

Last week, the owner of British Airways said it would try to recoup most of a €2bn (£1.7bn) hit in fuel costs this year through “revenue and cost management actions”, with fares likely to rise.

Fears over fuel shortages have also been compounded by airlines in the UK successfully lobbying for the ability to cancel more flights without risking valuable airport slots.

However, some reports suggest that some airlines are beginning to cut prices for summer flights to try to prevent a delay in bookings.

Analysis by the Financial Times found that air fares for a week-long trip in July dropped for 27 of the top 50 European flight routes to the Mediterranean between 9 April and 6 May.