Security authorities in the oil-rich kingdom on Monday handed eight Yemeni nationals, captured in Saudi Arabia in connection with various security matters, to counterparts in their southern neighbour, it said in a statement carried by the official SPA news agency.

  

Twenty-five Saudi nationals also wanted for security-related matters were handed to Saudi authorities in return, the ministry said.

  

The exchange falls within "the framework of shared efforts to strengthen cooperation between the two brotherly countries", it added.

 

Extradition treaty

  

Riyadh and Sanaa have exchanged dozens of suspects under a June 2003 security agreement which strengthened an extradition treaty signed in 1998.

  

The two neighbours also agreed last year to implement joint security arrangements to block infiltration and smuggling across their 1800km frontier.

 

In June 2000, they signed an agreement ending a decades-long territorial dispute.

  

Saudi Arabia has since May 2003 been battling a wave of Islamist unrest attributed to the al-Qaida network.

  

Under US pressure, Yemen has also cracked down on al-Qaida sympathisers in the wake of the 11 September 2001 attacks on the US.