RIYADH (AFP) — The authorities in Saudi Arabia have arrested another suspect in the February killings of four Frenchmen, the interior ministry announced on Sunday.

“Abdullah bin Sayer al-Mohammedi, a Saudi, was arrested last Sunday in a remote desert region northwest of Medina,” a ministry statement quoted by the official SPA news agency said.

“He was in possession of a machine gun which he tried to hide near where he was found,” it added.

Earlier, a normally reliable Saudi website said the suspect had been arrested in Chajwa village, around 80 kilometres (50 miles) northwest of the holy city of Medina.

Two other suspects were arrested in May and July. Authorities said the mastermind behind the attack, Walid Motlaq al-Raddadi, a 23-year-old Saudi who was among the most wanted suspected Al-Qaeda militants in the kingdom, was killed by police in Medina on April 6.

The four victims were in a party of nine French people from three families living in the Saudi capital Riyadh. On February 26, they were on an outing to Madain Saleh in northwest Saudi Arabia, a popular destination among expatriates.

They were killed when two people opened fire on them with machineguns after they lost their way 90 kilometres (55 miles) from Medina.

No claim of responsibility was ever made for the attack, which was the first in three months against Westerners in Saudi Arabia.

The oil-rich kingdom was rocked by a spate of bombings and shootings blamed on suspected Al-Qaeda militants that started in May 2003, triggering a relentless security crackdown on Islamist extremists.

The interior ministry has since warned Western governments of the danger of further attacks on foreigners, and the British and US embassies joined the French in issuing warnings to their citizens.