A roadside bomb hit a tourist bus on Friday in an area near the Giza Pyramids, killing three Vietnamese tourists and their Egyptian tour guide, and wounding 10 others, Egyptian officials have said.

The bus was travelling in the Marioutiyah area near the world-famous pyramids when the crude roadside bomb, concealed by a wall, went off, the interior ministry said in a statement. The ministry said the injured included 9 other tourists from Vietnam and their Egyptian driver.

Security services were immediately dispatched to the area, southwest of Cairo, and have opened an investigation into the explosion, the ministry added without giving further details.

There was no immediate claim of responsibility for the blast. As he visited the wounded in hospital, Prime Minister Mostafa Madbouli warned against “amplifying” the incident. “No country in the world can guarantee that it is 100 percent safe,” he said.

Attack on tourists ‘an attack on Egypt’s economy’

Egypt has battled Islamic militants for years in the Sinai Peninsula in an insurgency that has occasionally spelt over to the mainland, hitting minority Christians or tourists. However, this is the first attack to target foreign tourists in almost two years.

The attack takes place as Egypt’s vital tourism industry is showing signs of recovery after years in the doldrums because of the political turmoil and violence that followed a 2011 uprising that toppled former leader Hosni Mubarak.

It will likely prompt authorities to further tighten security around churches and associated facilities ahead of the New year’s Eve celebrations and next month’s Christmas celebrations of the Coptic Orthodox Church, the dominant denomination among Egypt’s estimated 10 million Christians.

Over the past two years, militant attacks against Christians in Egypt – usually targeting churches or buses carrying pilgrims to remote desert monasteries – have killed over a hundred people.

(FRANCE 24 with AP, AFP)