In a reference to both US-led forces and groups such as al-Qaida in Iraq, Grand Mufti Shaikh Abd al-Aziz al-Shaikh condemned the "murder of innocents by planes and bombs and attempts by suspect parties to trigger sectarian tensions between the people of Iraq".
The remarks on Sunday, carried by the pan-Arab Al-Hayat newspaper, criticised several parties for stoking inter-religious clashes "to serve the aims of the enemies conspiring against Muslims".
His comments follow a US bombing campaign in the northern Iraqi town of Tal Afar and a declaration of all-out war against Iraq's Shia population by Abu Musab al-Zarqawi, a Jordanian-born Sunni who has a $25 million price on his head.
Al-Zarqawi also warned all other religious and tribal groups that they should join his campaign or also face attack.
Shaikh Abdul Aziz al-Shaikh
condemned 'murder of innocents'
The Saudi mufti and his Council of Grand Ulamas (religious scholars) carry great influence in the Muslim world.
Iraq's main Sunni Arab religious authority, the Committee of Muslim Scholars, also last week condemned the al-Zarqawi call, made in an audio recording posted on the Internet last week.
Jordan's opposition Islamic Action Front (IAF) party has also denounced unnamed members of the Iraqi insugency for trying to stoke religious strife there, in an apparent reference to anti-Shia calls by al-Zarqawi.
"We strongly reject calls and fatwas (religious decrees) targeting part of the Iraqi people over their religious appurtenance," the IAF - which has 17 MPs in parliament and grassroot support in Jordan, said in a statement.
"We consider this a measure that exceeds the limits of religious law, logic and general interest, one that harms Iraq, its freedom and its independence and a contribution to dividing the country," the statement said.
Abu Musab Al-Zarqawi has a
$25 million prize on his head
The IAF praised the insurgency against the "Anglo-American occupation forces in Iraq" but said that "noble forces should unite against the occupation and schemes for internal fighting" in the neighbouring country.
The statement, which did not refer to al-Zarqawi or his group by name, also denounced the US-Iraqi offensive against the northwestern town of Tal Afar, which had been under rebel control.
It is the latest in a line of condemnations issued after the al-Zarqawi call, made in an audio recording posted on the internet last week.