Three Vietnamese tourists were killed and at least nine more injured when their tour bus was blown apart by a roadside bomb in Egypt.
Their Egyptian guide was also killed.
The attack took place just a few kilometres from the Giza pyramids.
It is the first attack on tourists in the country in more than a year.
It comes just as Egypt’s tourism industry has shown signs of recovery following previous deadly attacks.
Tourism plunged after the bombing of a Russian plane near Sharm el Sheikh in 2015.
The bus was carrying a total of 14 tourists from Vietnam.
The Egyptian bus driver was also injured.
"We were going to the sound and light show and then suddenly we heard a bomb. It was terrible, people screaming," said tourist Lan Le, who escaped unhurt.
Vietnam called on Egypt’s security forces to act quickly and bring the perpetrators to justice.
"Vietnam is extremely angered by and strongly condemns this act of terrorism. Vietnam requests that Egypt promptly launch an investigation into the case and track down those responsible," foreign ministry spokesperson Le Thi Thu Hang.
Egyptian authorities immediately took action, with about 40 suspected militants gunned down during raids in Giza and North Sinai, according to reports.
