As reported by Agence France-Presse Reuters SCMP, 05 July 2016
Muslims killing Muslims, worse, in Holy Sites:

Suicide bombers hit three Saudi cities in fourth terror attack in less than a week; four dead.
Suicide bombers struck three cities across Saudi Arabia on Monday, in an apparently coordinated campaign of attacks as Saudis prepared to break their fast on the penultimate day of the holy month of Ramadan.
Four Saudi security personnel were killed and five others were wounded in a suicide bombing outside one of Islam’s holiest sites, the Prophet’s Mosque in Medina, the interior ministry said.

“Security forces suspected a man who was heading towards Al-Masjid al-Nabawi (the Prophet’s Mosque) as he passed through a visitors parking lot. As they tried to stop him, he blew himself up with an explosive belt causing his death, and the death of four security personnel,” said the statement, adding that five others were injured.

The explosions targeting US diplomats, Shi’ite worshippers and a security headquarters at a mosque in the holy city of Medina follow days of mass killings claimed by the Islamic State group, in Turkey, Bangladesh and Iraq. The attacks all seem to have been timed to coincide with the approach of Eid al-Fitr, the holiday that celebrates the end of the fast. …
A Saudi security official said an attacker parked a car near the US consulate in Jeddah before detonating the device. The official said the government was checking the reports of blasts in Qatif and Medina.