Egypt's cafés, restaurants and shops are being told to close early from Saturday, March 28, under government rules aimed at saving energy during a shortage linked to the US and Israeli war with Iran.

In central areas of Cairo and in popular holiday resorts, many shops, bars and restaurants typically stay open until around 1 am or 2 am, allowing locals and tourists to enjoy milder evening temperatures.

However, Egyptian authorities have responded to a shortage of natural gas by ordering businesses, including shopping centres, across the country to close at 9 pm, in some cases several hours earlier than usual.

Street lighting and illuminated advertising billboards are also to be limited.

The shorter opening hours are prompting a backlash from holidaymakers in Egypt. People in popular seaside resorts such as Hurghada and Sharm el-Sheikh can also expect shorter opening hours from Saturday evening onwards.

"If things stay like this, I might as well stay at home," one user wrote in a Facebook group for German holidaymakers in Hurghada. "Tourism will be harmed more than helped," another wrote.

The reason is rising energy prices as a result of renewed conflict in the Middle East. Iran responded to attacks from the US and Israel by effectively closing the Strait of Hormuz, a key shipping route for global oil and gas supplies.

The government in Cairo hopes to counter its natural gas problems by reducing electricity consumption. Egypt generates more than 80% of its electricity with natural gas, much of which is imported. The most important gas supplier, Israel, stopped exports to Egypt when the war began more than three weeks ago.

The curfew for businesses is aimed at better rationing electricity and fuel, Prime Minister Mustafa Madbuli said, announcing the measure earlier in the week.

The measure is initially set to last one month and may be extended depending on how the war develops. Exceptions to the rule apply only on Thursday and Friday evenings, the Egyptian weekend, when openings until 10 pm are permitted. The working week in Egypt normally begins on Sunday.