Foreigners living in Saudi Arabia have been urged to remain vigilant and avoid unnecessary traveling following intelligence suggesting they may be targets of terrorist attacks.

Foreign embassies in Saudi Arabia were advised to alert their nationals after the authorities received intelligence that a group blamed for last month's killing of four French people could strike again.

"We have reacted immediately by informing our nationals of the warning which urged foreigners in general to be cautious and to call police as soon as they notice that they are being monitored," French embassy spokesman Alain Guepratte said.

Some French residents in Riyadh also confirmed that they had been informed by the embassy to avoid traveling to other cities.

The Interior Ministry said Tuesday that Saudi police have arrested several men suspected of being involved in the killing of four French nationals during a trip into the desert. But two Saudi nationals who masterminded the killing remain at large.

The ministry offered 1.9 million U.S. dollars for information leading to the culprits' arrest.

Source: Xinhua