A failed attempt on the life of Saudi Arabia's security chief could strengthen the position of his conservative father, Interior Minister Prince Nayef, in jockeying within the royal family over who becomes king next.

The attack by a suicide bomber posing as a repentant militant has refocused attention on the government's fight against Islamist insurgents, which Prince Mohammed bin Nayef has led since 2003, winning plaudits from US officials.

“The security apparatus, embodied by Prince Nayef and even his son, will wield greater influence on the kingdom's policy agenda,” a Western diplomat in Riyadh said.

The world's biggest oil producer, Saudi Arabia is an absolute monarchy without an elected parliament or rights to form political parties, where Sunni clerics control mosques, education, courts and their own public policing body.

King Abdullah is seen as a supporter of Western-friendly reforms which aim to reduce the religious establishment's hold on the country that produced Al Qaeda leader Osama bin Laden.

But diplomats say he has been stymied by conservative princes like Nayef, who maintains close ties to the clerics and does not want to upset the traditional balance of power between the religious establishment and the Saudi royal family.

Liberals fear for the fate of reforms if Prince Nayef were to be put in charge of the country, diplomats say.

Prince Nayef, believed to be 76, was appointed second deputy prime minister earlier this year, leaving him in charge of the country when King Abdullah and his appointed successor Crown Prince Sultan -- who are both in their 80s -- are abroad.

Prince Sultan has been out of the country since November because of unspecified illness and surgery, creating uneasiness over succession.

King Abdullah has set up an “Allegiance Council” of senior princes to vote on future kings and their deputies, but analysts say rivalry and jockeying for position in advance is intense.

The fight against Al Qaeda raises Nayef's profile.

Newspapers in recent days were full of panegyric articles about Prince Mohammed, with advertisements of thanks featuring the portraits of the king, crown prince, Nayef and his son.

“This attack adds to the credit of the interior ministry. It confirms the fact that Prince Mohammed bin Nayef has become the foe to beat for Al Qaeda,” said Khaled al-Dakhil, a Saudi politics professor. “It should get (his father) Prince Nayef a lot of credit among the senior royals.”

The attack was claimed by Al Qaeda in the Arabian Peninsula, which has regrouped in neighbouring Yemen. Saudi officials had talked of their concern that Yemen could become the launch-pad for a revival of the militant campaign in Saudi Arabia.

Nayef has had mixed success in persuading clerics to discourage radical ideology, which espouses violence against Muslims and Muslim governments seen as a un-Islamic.

Hundreds of suspects have been arrested since 2006 for seeking to form cells and Nayef admonished hundreds of clerics in 2007 for tacit or overt support for Saudis heading to Iraq.

He said they were being used as fodder for suicide attacks.

“The level of trust between Prince Nayef and the clerics is unmatched elsewhere,” a senior Arab diplomat said. “He has repeatedly criticised them for not toning down the rhetoric that breeds radicalism, yet they have always been like honey on butter.”

Christopher Boucek, an associate in the Carnegie Middle East Programme, wondered “Will the attempted assassination of his son lead him to be more direct in dealing with the clergy? It will be very interesting to see how that plays out.”

A stronger Prince Nayef could also embolden clerics in their opposition to reforms, since many of them argue that moves towards 'Westernisation', such as relaxing the kingdom's system of public gender segregation, encourages a zealous reaction.

The secrecy of the ruling family and political system means there could still be surprises, the Western diplomat said.

“(Nayef) is becoming the strong man of the regime. But whether this is because of the opacity that surrounds the succession issue remains to be seen,” he said.—Reuters