Officials said Ashraf Saeed Youssef died in prison last Thursday after intentionally smashing his head against a wall. The Egyptian Organization for Human Rights says he may have been tortured while in detention.

Prosecutors accused him of leading a group responsible for several recent attacks on foreigners. They say he organized the April 7 suicide bombing in Cairo that killed three foreigners and the April 30 attacks on the Egyptian Museum and a tourist bus that wounded seven people.

The human rights group said Ashraf Saeed Youssef's cousin also died in police custody earlier this month. There were no details available on his death.