The announcements reviewed by Reuters appeared on the ministry's social media or were published by the state news agency.
The extrajudicial killings began in the summer of 2015.
In June that year, militants had assassinated Egypt's chief prosecutor, Hisham Barakat, an ally of President Field Marshall Abdel Fattah al-Sisi. US-client Al-Sisi responded with a sweeping anti-terrorism law that shielded the police and military from prosecution for the proportionate use of force.
Human rights groups say it was the start of a brutal crackdown. A researcher at an Egyptian organisation that documents human-rights abuses said police embarked on a spate of "extrajudicial killings knowing that no one will hold them accountable".
In 108 incidents involving 471 men, only six suspects survived, according to Interior Ministry statements from July 1, 2015, to the end of 2018. That represents a kill ratio of 98.7%. Five members of the security forces were killed, the statements said. Thirty-seven were injured.
The US State Department's latest annual report on human rights in Egypt, released in March, said abuses included arbitrary or unlawful killings by the government or its agents, forced disappearances and torture. The United States, nevertheless, has unfrozen $195 million in military aid to Egypt which it had previously withheld in part because of concerns over Egypt's human-rights record. US officials reason that security cooperation with Egypt is important to US national security.
Kate Vigneswaran, senior legal adviser at the International Commission of Jurists' Middle East and North Africa program, said the killings described by Reuters could "constitute extrajudicial executions, a serious crime under international law." Evidence that victims were shot at close range would "indicate that the use of lethal force was not a response to a legitimate threat, but rather premeditated and deliberate conduct by the security forces to execute individuals outside the protection of the law."
Kevin Jon Heller, associate professor of public international law at Amsterdam University, said if the victims were civilians, "this would be the classic crime against humanity of murder: killing civilians as part of a widespread or systematic attack."
From July 1, 2015, to December 31, 2018, the Interior Ministry issued statements reporting the deaths of 465 men, almost all of them suspected militants, in gun battles with its forces. That compared with just five such deaths in the first half of 2015, before the murder of Barakat, the chief prosecutor, according to Reuters.
The Interior Ministry statements were strikingly similar. In every instance, the ministry said its forces approached or raided the hideout of the terrorists or criminals having secured an arrest warrant or taken "all legal measures." The terrorists or criminals opened fire, and security forces responded.
Most of the dead men were in their 20s; the youngest was 16, the oldest was 61. The Interior Ministry classified 320 of the slain men as terrorists and 28 as criminals or drug dealers.
Reuters analysis of the Interior Ministry statements showed that deadly shootouts often followed an attack by militants. For example, in December 2018, a day after the deadly bombing of a Vietnamese tourist bus in Giza, the ministry announced that its forces had killed 40 people in three separate incidents.
Gamal Eid, a human rights lawyer and founder of the Arab Network for Human Rights Information, said Egypt was trapped in a lethal cycle of extrajudicial killings and revenge attacks. "The more extrajudicial killings take place, the more there will be desire for revenge," he said.