Four security guards killed at Prophet’s Mosque in Medina in third attack to hit kingdom in one day.

At least four security officers have been killed and five wounded after a suicide bomb attack in Saudi Arabia’s holy city of Medina.

The bombing at the Prophet’s Mosque in the city of Medina was the third attack on Monday, following blasts in the cities of Jeddah and Qatif.

“Four security guards were martyred and five others wounded as a result of their opposition to the suicide attacker who detonated explosives near them as he was on his way to the mosque,” the ministry said on Twitter.

The Medina attack struck the security office of the mosque where the Prophet Muhammad is said to be buried, an important stop for millions of pilgrims who visit the holy cities each year. Four security officers died in the attack, Al Arabiya said, in addition to a suicide bomber.

The blasts in Saudi Arabia followed a bloody week in which terrorist attacks caused mass casualties in biggest cities of three Muslim countries: Turkey, Iraq and Bangladesh.

The blast struck moments before sunset prayers when people were breaking their fast inside the mosque in Madinah near the Prophet’s mosque, the Al-Haram Al-Nabawi, regarded as one of Islam’s holiest sites.

The mosque, which is also known as Al-Masjid an-Nabawi, is visited by pilgrims from around the world during the final days of the fasting month of Ramadan.

In Shia-dominated Qatif, on the Gulf coast, residents said a suicide bomber blew himself up outside a mosque frequented by the minority community. The blast appeared to target a Shia mosque. The attacker was killed but no other casualties were reported.

Earlier during the day, another suicide bomber detonated his explosives earlier near the US consulate in the city of Jeddah, injuring two security officers.

The incidents occurred shortly before the beginning of the Eid holiday, which follows the end of the holy month of Ramadan.

It was the first bombing in years to attempt to target foreigners in the kingdom. There was no immediate claim of responsibility for the Jeddah attack.