During Friday prayers Muslim clerics in the Arab world have strongly condemned Tuesday's attacks in America.
"It's not courage in any way to kill an innocent person, or to kill thousands of people, including men and women and children," says Sheik Mohammed Sayed Tantawi. Syria's most senior Islamic leader described the attacks on America as a terrorist act, as ignoble as what he called the state terrorism practised by Israel.
Hundreds of Palestinians also rallied in the West Bank city of Ramallah to show support for Americans killed in the attacks, as well as condemn Israeli killing of Palestinians in Jenin.
And in Iran, Tehran's main football stadium observed an unprecedented minute's silence in sympathy with the victims.
Iran's Ayatollah Imami Kashani spoke of a catastrophic act of terrorism which could only be condemned by all Muslims, adding the whole world should mobilise against terrorism.
There were many expressions of sympathy throughout the Arab world.
But if its roots were really to be tackled, terrorism and its practitioners would have to be defined, he said, pointing to Israel and calling it a "terrorist state which was killing children."
America's support and its arrogant policies around the world might help to explain the brutalism of the hijackers, he added.
On Thursday night, people who tried to stage a commemorative vigil in central Tehran, in spite of the ban on public gatherings, were broken up by police and Islamic volunteers.The head of al-Azhar in Cairo, one of Sunni Islam's highest religious authority, said attacking innocent people was not courageous, but stupid and would be punished on Judgement Day.
Christianity, America, or the Christian world were not accused because a Christian masterminded [the Oklahoma City bombing.]
"It's not courage in any way to kill an innocent person, or to kill thousands of people, including men and women and children," said Sheik Mohammed Sayed Tantawi.
In Lebanon the spiritual leader of the Shia guerrilla group, Hezbollah, called the attacks "barbaric acts."
He added even though Muslims were opposed to the American Government because of its support for Israel, the American people should not be blamed.
