Dozens of Egyptian police officers and conscripts were killed in what seemed to be a carefully orchestrated ambush by militants Friday, according to multiple news reports.
A statement from Egypt's interior ministry acknowledged the incident in broad terms but did not disclose details such as casualty figures.
At the time of publication, various press accounts were reporting differing numbers of those dead and injured in the attack.
Two wire services were told by sources within Egypt's security forces that police, acting on what they believed to be a credible intelligence tip, were lured to a suspected militant hideout only to be attacked with fire and rocket propelled grenades.
The apparent ambush took place late Friday in the desert about 80 miles southwest of Cairo, according to the AP, which called the incident "one of the single deadliest attacks by militants against Egyptian security forces in recent years."
Islamist militant groups have stepped up attacks within Egypt, particularly in the Sinai Peninsula that borders Israel and Gaza Strip, since a 2013 coup by the country's military removed the democratically elected president, Mohammed Morsi of the Muslim Brotherhood.
One such militant group is affiliated with ISIS and has killed hundreds of Egyptian security forces in recent years, says Reuters.
Some local news reports Saturday said Hasm, another extremist group, had claimed responsibility for the attack, but these claims appeared to be untrue, AFP reports.
No group has declared responsibility for the attack yet.