Jihadists killed an estimated 421 people and wounded at least another 729 in nearly 15 countries during the Muslim holy month of Ramadan this year, marking one of the bloodiest Ramadans in modern history.

The Islamic State (ISIS/ISIL) has been linked to the vast majority of the Ramadan casualties.

An assessment written for Al Arabiya by Sigurd Neubauer, a non-resident fellow at The Arab Gulf States Institute in Washington, suggests that Ramadan 2016, which began in June 5 and ends Tuesday, is indeed the bloodiest in recent times.

Neubauer notes, “The past 30 days have seen a string of high-profile terrorist attacks that have provided shock factors in regards to their timing, location and magnitude.”

The terrorist assaults this year intensified after ISIS jihadists issued their annual Ramadan call for violence in which they declared, “Ramadan, the month of conquest and jihad… make it a month of calamity everywhere for the non-believers.”

ISIS encouraged Muslims to carry out violent attacks against civilian and military targets “to win the great award of martyrdom” during the holy month, a period when martyrdom and engaging in jihad are especially valued and encouraged by radical Islamic extremists.

“According to Islamic practice, sacrifice during Ramadan can be considered more valuable than that made at other times, so a call to martyrdom during the month may hold a special allure to some,” warned the U.S. State Department-led Overseas Security Advisory Council following ISIS’s recent call for attacks.

This year, even the Prophet’s Mosque, one of Islam’s holiest site where the Prophet Muhammad is buried, was not spared.

The mosque is located in Saudi Arabia’s Medina, the holiest city in Islam after Mecca. The terrorist attack drew the ire of Muslims from all walks of life, including the Afghan Taliban terrorist group.

Monday’s attack in Medina followed a suicide bombing near the U.S. consulate in Saudi Arabia’s city of Jeddah that injured two security officers and two other suicide blasts targeting a Shiite mosque in the Kingdom’s city Qatif. Only the the suicide bomber was killed in Qatif.

“While these attacks remain unclaimed, the bombing near one of Islam’s most sacred sites, during its holiest month, has brought some additional clarity to international observers: Militants do not distinguish between Muslims or Westerns when it comes to killing civilians,” acknowledges Neubauer in the Al Arabiya report.

Some of the deadly terror assaults during the holy month include:

“While the latest string of high-profile terrorist attacks can be directly attributed to [ISIS’ Ramadan call to violence], ISIS has not only been able to successfully motivate extremists to affiliate with its radical ideology but also managed to convince them to pledge allegiance to the group at the time of the attack, even if no prior ties have been established – as seems to have been the case with Mateen,” notes the Al Arabiya analysis.

Breitbart News’ Ramadan casualties count excludes the estimated 22 jihadists who were killed in the attacks.