2 killed as bomb strikes tourist bus near Egypt's Giza pyramids

There were no immediate reports of any group saying it was behind the attack, but Islamist militants have targeted tourists in the past.

Two of the killed tourists are from Vietnam.

Egypt's tourist industry has been reeling in recent years from a serious of terror attacks as well as the Islamic State's downing of a Russian passenger plane, killing more than 200 holidaymakers returning from Red Sea resorts in Sharm el-Sheikh. The identity of the other injured person was unclear.

Dozens of police, military and firefighters were at the site, on a narrow side street close to the ring road, where traffic was moving normally.

The injured were taken to the nearby Al Haram hospital, where Prime Minister Mostafa Madbouly told local TV that the guide had died from his injuries.

The bus hit the device after it went off its planned route without alerting security forces, Mr Madbouly added.

More than 450 suspected jihadists and around 30 Egyptian soldiers have been killed since the offensive began, the army said in October. In total, 14 Vietnamese tourists had been travelling on the bus, it said.

Egypt has battled Islamic militants for years in the Sinai Peninsula in an insurgency that has occasionally spilled over to the mainland, targeting minority Christians or tourists.

Friday's attack however is the first attack to target foreign tourists in nearly two years.