The Saudi crown prince is on course to be first Saudi monarch from new generation.

Saudi Arabia's King Salman has embarked on a domestic tour this week with his favourite son, demonstrating his support for his chosen heir despite the crisis spawned by the murder of journalist Jamal Khashoggi.

Roads were lined with Saudi flags and images of the king and his son Crown Prince Mohammed bin Salman, when they arrived in the central region of Qassim late on Tuesday. Distinguished figures greeted them and children offered flowers.

The tour is the latest public outreach by the 82-year-old monarch, apparently intended to shore up the power of Prince Mohammed, known as MbS, who has taken over day-to-day rule but whose international reputation was battered in the month since Khashoggi was killed in the Saudi consulate in Istanbul.

State media said the king laid the foundation for new or planned projects worth $1.12 billion and ordered the release of some people from debtors' prison in Qassim, a conservative province in the heart of the Arabian peninsula.

"There is a lot of tension, fear and apprehension among Saudis in the aftermath of the Khashoggi affair. So it's a trip that reassures the various regions that the king is still in his place and he's the highest authority," said Madawi al-Rasheed, a London-based Saudi author critical of the Al Saud.

Turkish officials have accused MbS of ordering Khashoggi's murder. U.S. President Donald Trump has suggested ultimate responsibility lies with the crown prince as de facto ruler.

Saudi Arabia, which offered numerous contradictory explanations for Khashoggi's disappearance, now says the U.S.-based Washington Post columnist was killed in a rogue operation. MbS broke weeks of silence on Oct. 25 to vow justice would prevail.

King Salman stepped in to defuse the situation. He sent a trusted aide to Turkey last month, then fired five senior officials, including his son's most trusted adviser.

After weeks of lying low, the prince has now returned to the public stage. He visited troops near the border with Yemen, where Riyadh is involved in a 3-1/2-year war, appearing in an online video on Monday with a soldier he called a hero. In a ceremony at a Riyadh university, he laid the foundation stone for a planned nuclear research reactor.

Greg Gause, a Gulf expert at Texas A&M University, said the domestic tour with his father did not indicate that the royal family is in the clear yet, only that "the king is confident that nothing is afoot right now."

CIRCLING THE WAGONS

The 33-year-old crown prince is on course to become the first Saudi monarch from a new generation in 65 years, following a succession of six brothers drawn from among at least 45 sons of state founder Abdulaziz ibn Saud, who died in 1953.

But MbS's rise has upended the system of rule in place for decades, in which successive kings sought family consensus and allocated powerful posts to their brothers and nephews.

MbS consolidated his rule by stripping some of his most powerful cousins from positions of authority and locking some under house arrest. Others were caught up in an anti-corruption crackdown and confined inside a luxury hotel for months.

There have been signs since last week that some princes are being rehabilitated to foster family unity in the wake of the Khashoggi killing. Last week, one of the king's surviving younger brothers, Prince Ahmed bin Abdulaziz, returned from 2-1/2 months abroad where he had appeared to criticise the leadership.

Two of the king's nephews, detained last year, appear to have been released recently, with pictures circulating of them reuniting with family.

Diplomats say the ruling family is "circling the wagons". But there is no indication King Salman is considering elevating another prince, either to replace his son or balance his authority by serving as his deputy.

"MbS is not going anywhere. The family is meeting and they will unite stronger behind him," said a senior Arab diplomat. "There is no way back" after the king cleared MbS's path to the throne by sidelining potential rivals last year.

The king's decision to put MbS in charge of restructuring the intelligence apparatus - a move aimed at addressing a purported cause of the Khashoggi crisis - indicates that the crown prince remains "untouchable", the diplomat added.

On Tuesday evening, as King Salman and MbS arrived in Qassim, north of Riyadh, to a stadium of cheering residents, online photos emerged showing Prince Abdulaziz bin Fahd with his brothers and daughters in a residential setting.

The images were the first of the prince, the son of a former king, since his detention, which the government never acknowledged. It was not made clear whether he had reached a settlement with the state like other detainees who were subsequently released, or if his freedom is still restricted.

Over the weekend, another of the king's nephews, a brother of billionaire investor Prince Alwaleed bin Talal, was photographed at his ailing father's bedside after being held for months over online criticism of the anti-corruption purge ordered late last year by MbS.

The next day Alwaleed, who was among scores of top royals, businessmen and government officials held at Riyadh's Ritz-Carlton Hotel as part of the sweep, went on Fox News to defend MbS in the Khashoggi crisis and the anti-corruption campaign.

"I believe the Saudi crown prince will be 100 percent vindicated and exonerated," Alwaleed said of his cousin. Alwaleed's own detention was "forgiven and forgotten," he said.