Saudi Arabia will hit hard those who seek to harm its young people, King Salman said today after suicide bombers struck Islam's second-holiest site and two other targets.
In a speech marking the eve of the Muslim Eid al-Fitr holiday, Salman, 80, also cautioned young people against "the dangers that lie in wait, notably extremism".
He said the country "is determined to strike with an iron fist all those who want to harm the spirit and orientation of our youth".
More than half of Saudis are under 25 and some have proclaimed allegiance to the Islamic State group of jihadists.
The speech was given in Salman's name by the information minister and carried by the official Saudi Press Agency on the occasion of Eid al-Fitr tomorrow.
The holiday is celebrated by Muslims worldwide to mark the end of the holy fasting month of Ramadan.
Salman was commenting the day after a suicide bomber in Medina killed four police outside the Prophet's Mosque, Islam's second-holiest site.
The attack, which sparked condemnation across the Muslim world, coincided with another suicide blast in Shiite-dominated Qatif, in the kingdom's east, where the only casualty was the bomber.
Early yesterday a third suicide bomber wounded two policemen when he blew himself up near the United States consulate in Jeddah.
That attacker was a Pakistani resident of the kingdom, the interior ministry said.
It has not identified the others, and there has been no claim of responsibility.
The IS group has previously claimed other attacks against Saudi security officers and minority Shiites.
