By Richard Hamilton
BBC News, Morocco
Human rights activists in Morocco are demanding an investigation into the death of a man in prison.
Thousand of Moroccans were arrested after the 2003 attacks
Zakaria El Miloudi was arrested along with thousands of others following a series of suicide bombings which killed 41 people in Casablanca in May 2003.
He is the second person from the 2003 arrests to die in custody, after the death of a hunger striker last year.
It is not clear how Mr El Miloudi died, but it is thought that he was suffering from asthma.
Abdurrahim Mouhtad of the human rights association An-Naseer says they are devastated by the news.
"We are very moved and saddened to have lost someone who is a Moroccan and a Muslim because we believe he was innocent," he said.
"And those who found him saw that he had died far from his children and his family, far from his home in a cell with a locked door in a detention centre - it's very sad, very sad."
The human rights group says it will wait to hear the results of an autopsy but it cannot understand how a man who suffered minor ailments came to die in his prison cell.
In Morocco, the date of 16 May 2003 is as familiar as 11 September in the United States.
The authorities cracked down swiftly on suspected Islamic militants and arrested thousands of people.
Although Morocco has been praised in particular by the United States for its tough stance on terrorism it seems the human cost of that approach is mounting.