CAIRO, Egypt (AP) _ Saddam Hussein's security forces have arrested about 600 people since last month's assassination attempt on his son, a leader of the Iraqi opposition said Friday.

Those detained include more than 20 senior officers and officials, said Wafiq al-Samarra'i. A former army intelligence chief, al-Samarra'i has lived in exile in Damascus, Syria, since defecting two years ago.

He said the roundups took place in the capital, Baghdad, and other cities in central Iraq, Saddam's stronghold.

A leading Arabic-language newspaper reported that four men carried out the Dec. 12 attack on Odai, and said the assailants already have fled Iraq.

Saddam's eldest son and heir apparent, Odai, was wounded in a grenade and machine-gun attack as he drove through Baghdad. Every interview with him since on Iraqi television has shown him in a hospital bed with his legs and much of his torso covered.

The footage has never shown him moving his back or legs, suggesting that he may be paralyzed, al-Samarra said.

The London-based al-Hayat newspaper said the men who carried out the attack hid with Bedouin tribesmen in western Iraq for four days before making their way out of the country.

They were accompanied by Raad al-Hazaa, a former army officer believed to be the mastermind of the attack, the newspaper said.

The men went from Jordan to the United Arab Emirates before taking refuge in Europe, the newspaper said. It cited an unidentified Iraqi opposition figure in London as its source, and did not specify where in Europe the men are hiding.

Other Iraqi dissidents have named al-Hazaa as a key figure in the attack. Al-Hayat said he was seeking to avenge Saddam's execution of his uncle Gen. Omar al-Hazaa in 1986.

The younger al-Hazaa used ties to Saddam's relatives to track Odai's movements, the Saudi-owned Al-Hayat said.

Al-Samarra'i said the round of arrests will have little impact on the Iraqi opposition, much of which is abroad.

``The people and the army do not want Saddam, the events prove it and more operations will take place,'' he said in a statement faxed to The Associated Press in Cairo, Egypt.