Saudi Arabia announced on Sunday the arrest of 28 al Qaeda linked suspects for planning attacks in the oil-rich kingdom, following an alleged plot to commit a "terrorist act" during the annual Muslim pilgrimage, or haj.
"Since December 14, 28 members of the deviant group (the term used by the Saudi authorities for al Qaeda) have been arrested, including one foreign resident and the rest Saudi nationals," an interior ministry official said in a statement carried by the official SPA news agency.
The statement said the suspects were "linked to elements abroad and were planning criminal acts in the kingdom," an expression Saudi authorities use to describe al Qaeda attacks.
The suspects were captured in the provinces of Mecca, Medina, Riyadh and the area around the kingdom's northern borders, the statement said.
It added that it was in the "general interest" to withhold further details of the nature of the plots and the planned targets.
The Saudi authorities have been battling a wave of deadly violence waged by Islamist militants since 2003. On Friday, the interior ministry said that security forces had arrested an al Qaeda-linked group planning a "terrorist act" during the haj, which this year attracted about 2.5 million Muslims from across the globe.
The pan-Arab newspaper al-Hayat reported on Saturday that seven non-Saudi Arabs had been arrested over the plot. It said the arrests had not been announced earlier to avoid creating panic among the hundreds of thousands of pilgrims to Islam's holiest sites in and around Mecca in western Saudi Arabia.
Interior ministry spokesman General Mansur al-Turqi said on Friday as the haj was winding down that the militants "planned to carry out a terrorist act aimed at harming security and damaging the haj." However he said the attack did not specifically target holy sites in Mecca or the pilgrims.
The authorities were on high alert this year because of the participation of Iran's Mahmoud Ahmadinejad, the first president from the Islamic republic to take part in the haj.
Interior Minister Prince Nayef bin Abdul Aziz said in early December that his forces had foiled "more than 180 terrorist operations" since a wave of bombings and shootings by the Saudi branch of al Qaeda erupted four years ago.
The conservative Muslim kingdom also said it arrested 208 suspected al Qaeda militants over the past few months who were plotting assassinations and an attack on a logistical oil facility.
The militants, who are followers of Saudi-born al Qaeda chief Osama bin Laden, espouse the ideology of "takfeer" - branding other Muslims as infidels in order to legitimise violence against them.
The haj, which all Muslims are expected to perform at least once in a lifetime if they have the means, has been hit by a series of disasters over the years, mostly caused by stampedes or fires.
There were no major incidents reported during this year's celebrations. However, in December 1979, 151 people were killed and 560 wounded after Saudi security forces stormed the Grand Mosque in Mecca to rescue pilgrims held hostage by Islamist militants for about two weeks.
And in July 1989, one person was killed and 16 were wounded within the Grand Mosque sanctuary in a double attack blamed on 16 Kuwaiti Shiites who were executed later the same year.
Four hundred and two people were killed, including 275 Iranians, according to official Saudi figures, when security forces tried to break up an anti-US demonstration by Iranian pilgrims during the haj in July 1987.