Saudi Arabia's Interior Minister says his security forces will do their utmost to keep the peace during the annual Muslim pilgrimage, or Hajj.  But he does not discount the possibility of attacks by recent infiltrators from Yemen.

Saudi special forces conduct drills in Mecca as preparations continue for the annual Hajj, or muslim pilgrimage.  Armored personnel carriers, ambulances, fire engines, police vehicles, helicopters and planes are used in the exercises to simulate a response to violence or a natural disaster.

Check points and security controls have been set up on the outskirts and along roads leading into the cities of Mecca and Medina.  Saudi security officials say that no one will be allowed to enter either city or to participate in the Hajj without a permit.

Saudi TV showed security forces stopping civilian vehicles and buses carrying pilgrims at checkpoints to show their passports, IDs and permits.

Interior Minister Prince Nayif bin Abd al-Aziz Al Saud says his forces are ready to prevent violence during this year's Hajj and will take take all necessary steps to ensure the safety every pilgrim.

He says officials are asking everyone to respect the sanctity of the Hajj and of the holy cities and are warning they will not tolerate any acts of violence.  He insists Saudi security forces are taking every possible measure to prevent individuals or groups from tampering with the security situation and he vows to guarantee the safety of all pilgrims.

The interior minister also told reporters he is worried about the security situation in light of the ongoing conflict along the border with Yemen and stressed that his forces were keeping an eye out for possible sabotage or violence by rebels who may have infiltrated the country.

He says he hopes none of the infiltrators will attempt to desecrate the pilgrimage, but if anyone attempts to commit acts of violence, he says authorities will protect every inch of our soil.

The interior minister went on to emphasize that he "does not exclude the possibility of coordination" between the infiltrators and al-Qaida in carrying out possible attacks during the Hajj.

Saudi Mufti Abdul Aziz Al Sheikh also told a religious conference that Muslims must "not commit violence against other Muslims."

He says that it is the duty of every Muslim to cooperate and to behave in a peaceful manner and not to aggress or attack anyone.

Saudi TV noted security forces used helicopters and artillery to inflict what they described as "heavy casualties" on rebel fighters along the Yemeni border and among those who were attempting to infiltrate Saudi territory.  It said the Saudi navy has also carried out maneuvers to prevent infiltration by sea.