An Egyptian opposition party on Monday blamed President Mohamed Morsi and the Interior Ministry for the deaths of two of its activists - one of who was allegedly tortured in police custody, dpa reported.
Mohamed al-Gindy and Amr Saad died Monday in Cairo hospitals.
A health official told state media that al-Gindy suffered from low blood pressure and a suspected brain haemorrhage. However, activists claimed his body bore torture marks.
The Popular Current party, led by former presidential candidate Hamdeen Sabahy, said al-Gindy was "tortured to death."
He was reportedly kidnapped by police in central Cairo late January and was found in intensive care four days later.
Saad was injured during Friday's clashes between protesters and security forces outside the presidential palace in north-eastern Cairo.
"The Popular Current holds the president and the Interior Ministry the political and criminal responsibility for their innocent blood and asserts that it will pursue retribution," the party said.
Their deaths come amid increasing public anger against police brutality during last week's clashes, in which more than 60 people died across the country.
The Interior Ministry said 396 policemen have been injured in these protests since January 25.