Moroccan authorities have arrested a man alleged to be a leading member of Osama Bin Laden's al-Qaeda network, say US officials.

The Saudi national, Abu Zubair - nicknamed "The Bear" for his huge frame - is suspected of planning attacks against Western interests in Morocco.

The Moroccans can use much more persuasive methods in questioning a suspect

US official

Another senior al-Qaeda agent, German citizen Mohammed Haydar Zammar, who was also arrested by Morocco, has been handed over to Syria where he is being interrogated, Reuters news agency reported citing US authorities.

The BBC's diplomatic correspondent, Barnaby Mason, says the two arrests show how the United States is using information gathered in interrogations by other countries' security forces.

US officials have said they are in no hurry to take custody of Abu Zubair because the Moroccans "can use much more persuasive methods in questioning a suspect," ABC television reported.

Interrogation information

According to US officials, Abu Zubair's alleged activities included:

• Running some of Bin Laden's training camps in Afghanistan before 11 September
  
• Helping evacuate al-Qaeda forces from Afghanistan during the US-led war against the Taleban and al-Qaeda
  
• Being a close associate of Abu Zubaydah, the senior al-Qaeda operations chief captured in Pakistan and being questioned by US authorities
  
• Being central to al-Qaeda's international recruiting network, accepting recruits into training and placing them in overseas cells.

There is no evidence to link him directly with the attacks on the United States.

Our correspondent says it is clear that the Americans have access to whatever information emerges from the Moroccans' interrogation of him.

They also appear to have been given information from the interrogation of Mr Zammar in Syria.

US officials suspect Zammar recruited the chief 11 September hijacker

A senior State Department official told a congressional committee that co-operation from the Syrians had saved American lives.

An investigation by the German television station, ZDF, and the Washington post says the Americans have had contact with Mr Zammar for several months.

US officials suspect he was responsible for recruiting Mohammed Atta, the alleged ringleader of the group which launched the 11 September attacks on New York and Washington.

German officials, who have been trying without success to gain access to Mr Zammar, are sceptical that there is sufficient evidence to link him closely with the hijackers.

Series of arrests

Confirmation of the two arrests comes after Morocco recently admitted arresting seven others who are being charged with targeting American and British naval ships in the Straits of Gibraltar.

In another development, Saudi Arabia announced on Tuesday its first arrests linked to al-Qaeda.

Thirteen people suspected of plotting to attack targets in Saudi Arabia have been detained some months ago.

The 11 Saudis, an Iraqi and a Sudanese man were involved in an alleged plan to shoot down a US military plane taking off from a Saudi air base, the government said.