Funerals were held in several provinces for those killed, whose coffins were wrapped in Egyptian flags.
The official toll from the interior ministry was lower than a figure given earlier by security and medical sources of at least 35 Egyptian police officers killed in the clashes which began on Friday night.
The ministry said it had sent police to the area, less than 200 kilometres (125 miles) southwest of Cairo, after learning that militants were there “hiding, training, and preparing to carry out terrorist operations”.
As the forces approached, the militants opened fire with heavy weapons, triggering a shootout that lasted for several hours and also left 13 police officers injured and one missing, the ministry said.
There has not yet been a claim of responsibility. A fake claim in the name of the small extremist group Hasam, reported by multiple local media, had spread on social media soon after the shootout.
Authorities are fighting the Egyptian branch of the Islamic State group, which has increased its attacks killing hundred of soldiers and police in the north of the Sinai peninsula, more than 500 kilometres (300 miles) away from the latest violence.
– Armoured vehicles –
On Saturday armoured vehicles were seen parked on the road close to where the incident took place along with about 15 ambulances.
The ministry said that 15 militants were killed as security forces chased them into the desert after the clashes, adding that the search for suspects was continuing.
The public prosecutor has ordered the state security prosecution to start an investigation into the incident, an official said.
According to a source close to the security services, the police convoy was hit by rocket fire. The attackers also used explosive devices.
President Abdel Fattah al-Sisi was scheduled Saturday to attend events in the northern town of El Alamein on Egypt’s Mediterranean coast to mark the 75th anniversary of the pivotal Allied World War II victory in the Battle of El Alamein.
But an AFP reporter did not see the strongman leader at an open-air ceremony involving foreign dignitaries, and his office said he had cancelled his participation in a number of other engagements.
Sisi’s office, though, said he visited El Alamein Military Museum with some of the dignitaries, and gave a speech commemorating the battle and stressing the Middle East “is facing unprecedented crises”
Since the army in 2013 removed elected Islamist president Mohamed Morsi of the Muslim Brotherhood, extremist groups have increased their attacks on the military and police.
Condemnations of the latest attack came in from the Middle East and Europe, with France — where Sisi is due to visit next week — pledging solidarity after the losses for Egypt’s security force in “the fight against terrorism”.
The Muslim Brotherhood, once Egypt’s largest opposition movement, has long denied involvement in the attacks on the authorities.
Morsi was elected Egypt’s first civilian president in 2012, but the army overthrew him a year later following mass protests against the Islamist’s divisive rule.
– Competing wings –
Since then, an extensive crackdown on the group has left it in disarray with competing wings that have disagreed on whether to resort to violence, after police bloodily suppressed their protests.
Analysts say a section of the Brotherhood has encouraged armed assaults against the police.
Hasam has claimed multiple attacks since 2016 on police, officials and judges in Cairo.
Earlier this month, Sisi extended for a second time a state of emergency first declared after bombings claimed by IS in two churches that killed at least 45 people in April.
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