RIYADH, 30 January — Security authorities have warned pilgrims against using the annual Haj for political propaganda and said officials are keeping a close watch on thousands of them arriving in the Kingdom by land, air and sea.

“We have not taken any extraordinary measures for this year’s Haj in the aftermath of the Sept. 11 attacks, but we are monitoring matters closely to prevent any outlaws from sneaking in for the Haj and spoiling it,” a security official said.

Airport officials said more than 150,000 pilgrims have arrived in the Kingdom. About two million people are expected to perform the Haj this year.

The pilgrims are flocking to the Kingdom amid tight security around the world in the wake of the Sept. 11 attacks on New York and Washington. Tensions have been high in the area, following the September attacks and subsequent US military strikes on Afghanistan.

A Kuwaiti newspaper recently quoted intelligence sources as saying some Al-Qaeda members who might have escaped Afghanistan might try to enter the Kingdom during the Haj season, which starts on Feb. 21.

US and Western forces have been combing Gulf waters for suspected Al-Qaeda supporters who might have fled Afghanistan.

A senior Western diplomat in Riyadh downplayed chances of disruption to the pilgrimage, but acknowledged it could be used as a platform by some militant elements to air their message. He said the Saudi authorities are alert to potential threats.

“Our security measures are clear. The Haj season is one of worship and not for political statements or slogans aimed at distracting pilgrims from their religious duties,” the security official said, adding that signs, pictures or effigies are banned. The Kingdom usually urges pilgrims to refrain from any political activity during the annual pilgrimage.

Haj, one of the five pillars of Islam, must be performed at least once in a lifetime by every able-bodied Muslim who has the financial means. According to a Hadith of Prophet Muhammad (peace be upon him) those who perform Haj with a sincere heart will become as pure as the day they were born.

More than 1.36 million pilgrims from around the world, joined by 440,000 from inside the Kingdom, performed the Haj last year.