CAIRO (AP) — Egyptian authorities detained two police officers on Thursday over allegations that they had tortured a lawyer to death inside a police station, the latest in a series of recent incidents that underline alleged abuses by the country's police force.

The detentions came after Prosecutor Mohammed Abdel-Shafi, in the Eastern Cairo prosecution department, summoned seven policemen from the station where the incident took place for questioning. The two have not been charged and the other five were released.

According to Interior Ministry spokesman, Abdel-Fattah Osman, the slain lawyer Karim Mohammed was detained after joining Islamists' demonstration on Monday in el-Matariya district — a hotspot for clashes between security forces and protesters during near-weekly demonstrations.

Osman said Mohammed's death was caused by a "circulatory collapse."

But dozens of lawyers, angered what they said was evident police impunity, staged a demonstration in front of the lawyers' union headquarters in Cairo.

They declared a seven-day mourning period for their colleague, covered the building in black cloth and played Quranic verses over a loudspeaker.

Karim's death is one of dozens of cases reported by rights groups and media in what they say are instances of torture-to-death inside crammed police stations.

Since Egypt's army chief-turned-president Abdel-Fattah el-Sissi led the ouster of Islamist President Mohammed Morsi in 2013, security forces have unleashed an extensive crackdown on Morsi's supporters and branded his Islamist group, the Muslim Brotherhood, a terrorist organization.

There are concerns that violations of human rights and abuses by the police are going unchecked amid the crackdown.

A security official told The Associated Press said that this is the third death in the past three days in the same police station but insisted the deaths stemmed from "natural causes," not torture.

The two other fatalities were a suspected drug trafficker and an alleged Islamist protester, said the official, who spoke on condition of anonymity because he was not authorized to speak to the media.

Lawyer Mohammed Osman, who is the head of Northern Cairo lawyer's union, said that without curbing the tide of police abuses and holding officers' accountable, "this government would be significantly undermined."