RIYADH, Saudi Arabia (AP) _ Saudi Arabia's security chief Thursday threatened to crack down on Islamic fundamentalists who have criticized the nation's more moderate religious scholars and political leaders.

''Punishment is severe for anyone who infringes on the rights of society,'' Gen. Abdullah bin Abdul-Rahman al-Sheik said in a statement published in the Asharq al-Awsat daily newspaper.

''We will confront all the elements of sick minds that are a residue of the gulf crisis.''

King Fahd has made clear he is determined to curb a wave of fundamentalist militancy, attributed in part to a backlash from the deployment of non-Muslim Western forces on Saudi soil.

Fundamentalists said the presence of so many non-Muslims threatened to contaminate the country's religious purity.

The hard-liners have launched vilification campaigns against the nation's moderate Islamic scholars, political and economic leaders, and even members of the royal family.

Security organs will show ''no mercy'' to troublemakers, al-Sheik said. ''We shall use the necessary firmness in dealing with their weakness.''

The government's own religious police - the Mutawa, or ''enforcers'' - are seen by many here as contributing to the post-Gulf War backlash. Liberal Saudis and foreigners have reported almost daily confrontations with the cane- wielding Mutawain, mostly young Islamic zealots.

They Mutawain beat people who don't stop for the five-times-a-day prayers prescribed in the Koran, and jab women with sticks for showing naked arms or legs.

Shopkeepers in Riyadh, the capital, threatened in December to close unless the zealots stopped harassing women customers.

Fahd told his cabinet Monday that ''if matters go beyond their limits, then we will deal with them when we get to that point.''

The fundamentalists growing militancy also stems from Fahd's plan to create a ''consultative council'' that would allow selected citizens to offer opinions to the government. The militants that such a council would spawn dilution of the country's religiosity.

In December, the kingdom's leading theologian, Sheik Abdel-Aziz ibn Baz, lashed out at the fundamentalists' actions as ''against the teachings of Allah.'' Since then, police have banned about 15 militants from preaching.