The alleged attacker has been arrested and is now being questioned by police.
Egypt is facing a threat from an Islamist insurgency and the tourism industry is taking a hit.
The policemen were part of the force tasked to guard the district of Saqqara, one of Egypt's most popular tourist sites and host to a collection of temples, tombs and funerary complexes.
It has sought to attack foreign nationals in mass atrocities, such as the downing of the Russian MetroJet aircraft in October 2015 that left 224 dead, as well as low-level attacks.
All the victims of the attack in the Red Sea resort town of Hurghada were female.
Tourist numbers in the resort had only just started to recover from the impact of earlier terror attacks across Egypt.
As with the beach stabbing, there has not yet been any claim of responsibility for the attack. But the attacks have spilled to urban areas including capital Cairo.
Egypt Hurghada stabbing: Two tourists killed at Red Sea resort
"We now have the sad certainty that two German women were killed in the attack in Hurghada", a German Foreign Ministry spokeswoman told the newswire.
The interior ministry also announced early this week the killing of six militants in Southern Egypt as security forces faced militants in gunfire exchange.
However, despite a partial travel warning by Germany's Foreign Ministry, which was originally issued on July 5 and labeled current as of July 15, Egyptian radio reports that more than 1,500 German tourists arrived in Hurghada airport on Saturday alone.
Yesterday's attack is at the same resort where three tourists were injured in a knife attack by two suspected ISIS sympathisers in January 2016.
Since the overthrow in 2013 by the egyptian army of president Mohamed Morsi, from the muslim brotherhood, extremist groups have multiplied the attacks against the military and police, killing hundreds of them, mainly in the Sinai peninsula. Authorities outlawed the Brotherhood a few months later, declaring it a terrorist group.
According to him, the assailant was a 28-year-old native Egyptian province of Kafr El-Sheikh, by the name of Abderrahman, Shams al-DIN. Egypt's Christians account for about 10 percent of the country's 93 million people.More news: China trading more with North Korea but buying less coal