It was unclear whether the raids were directly connected to Friday’s attack. Egypt’s interior ministry said only that 30 of those killed during two raids on hideouts in Giza were “terrorist elements” planning attacks on state, tourist Christian targets.
“Information was received by national security that a group of terrorists were planning to carry out a series of aggressive attacks targeting state institutions, particularly economic ones, as well as tourism, armed forces, police and Christian places of worship,” the statement said.
Police found a large number of weapons, ammunition and bomb-making materials, it added.
Security forces also killed 10 suspected militants in the north Sinai capital, Arish, where the country is fighting an insurgency led by Islamic State.
The Egyptian state news agency MENA said the suspects, described as “terrorists seeking to intimidate Egyptians”, were killed in a gun battle. It did not say whether there had been any casualties or injuries among the security forces.
The raids follow the deaths of three Vietnamese tourists and their Egyptian tour guide in the bus attack on Friday.
Eleven other Vietnamese people and the vehicle’s Egyptian driver were injured in the blast after the detonation of an improvised explosive device reportedly hidden near a wall on the outskirts of Cairo. No group has claimed responsibility for the attack.
It was the first attack on foreign tourists in Egypt in more than a year, after security forces launched a campaign against militant groups in the Sinai peninsula, southern areas and the border with Libya.
Geoffrey Adams, the British ambassador to Egypt, tweeted after the bus attack: “Our hearts go out to the families of the victims and all those affected in today’s incident in Giza, and to the Egyptian authorities as they respond. The UK stands with Egypt in the fight against terrorism.”
Tourism has been one of the main drivers of Egypt’s struggling economy, contributing around 11per cent of GDP in 2017, or 375bn Egyptian pounds (£16bn).
The country has intensified efforts to reverse a steep fall in the number of visitors to the country following political turmoil linked to the 2011 revolution.
Egypt’s Red Sea resorts were sheltered from the worst of the upheaval, but tourism fell dramatically following an explosion aboard a Russian plane over the Sinai peninsula in October.
The explosion claimed the lives of all 217 passengers and seven crew members after the plane took off from Sharm el-Sheikh airport.
Holidaymakers were evacuated from a hotel in Hurghada in August following the death of a British couple.
The tour operator Thomas Cook cited concerns about “a raised level of illness among guests” that was later found to be connected to e-coli poisoning.
Targeted campaigns promoting tourism have accompanied state-sponsored international conferences designed to encourage foreign investment.