Abd al-Malik Muhammad Yusuf Uthman Abd Al Salam (also known as Umar al-Qatari and Umar Al-Tayyer عبد المالك محمد يوسف عثمان عبد السلام) is a jihadist of Palestinian Jordanian origin, who also holds a Qatari national ID.
 He is a U.S. and UN designated terrorist due to his financial, material, and technological support of Al-Qaeda and the Al Nusra Front.
Hashim al-Shaykh (Arabic: هاشم الشيخ‎ ‎ ), also known by his "nom de guerre" Abu Jaber Shaykh (Arabic: أبو جابر الشيخ‎ ‎ ) is a rebel commander during the Syrian Civil War who is a senior leader of Tahrir al-Sham.
 He had reportedly resigned from his position in Ahrar al-Sham where he served as a senior commander to help command and direct the merger.
 Abu Jaber is a Sunni Muslim with a Salafist jihadist ideology, which is reflected in the ideology of the group he leads.
Mala Abdul Karim Mudarris or Shaykh Abdul Karim Mudarris (1901–2005) (Kurdish: Mele Ebdulkerîmê Muderîs) also known as Nami was the contemporary Kurdish poet, writer, translator, Faqih and the Mufti of Iraq.
 Most of his works are in Kurdish and Arabic and a few of them are in Persian.
 He is known for his numerous literary, historic and religious works like the collection and expounding of the poems of Kurdish poets like Nalî, Mahwi and Mawlawi Tawagozi.
 He has influenced many Kurdish students and many recent imams and polymaths.
 Many of his works have not been published.
 Sir Abdulkarim was very good at writing poems and had written many books and dictionaries such as (DOO RSHTAH), which is a dictionary which defines Arabic words in poem in Kurdish.
 He was the first person to translate Holy Quran into Kurdish.
Abu Sayyaf ( ; Arabic: جماعة أبو سياف‎ ‎ ; "Jamāʿat Abū Sayyāf ", ASG; Filipino: "Grupong Abu Sayyaf" ), unofficially known as the Islamic State of Iraq and the Levant – Philippines Province is a Jihadist militant group that follows the Wahhabi doctrine of Sunni Islam based in and around Jolo and Basilan islands in the southwestern part of the Philippines, where for more than four decades, Moro groups have been engaged in an insurgency for an independent province in the country.
 The group is considered violent, and was responsible for the Philippines' worst terrorist attack, the bombing of Superferry 14 in 2004, which killed 116 people.
The Free Sunnis of Baalbek Brigade, also known as the Ahrar al-Sunna Baalbek Brigade, is a Sunni jihadist group active in Lebanon.
 It first rose to prominence in November 2013 when it retaliated against the Shia Islamist group Hezbollah, after clashes between locals Sunnis in Baalbek and members of Hezbollah.
 The group is known for attacking the Iranian embassy in Beirut in 2013 and attacking Christian churches.
 On 30 June 2014, the group pledged its allegiance to the Islamic State of Iraq and the Levant (ISIL).
The Islamic State of Iraq and the Levant (ISIL, ), also known as the Islamic State of Iraq and Syria (ISIS ), Islamic State (IS), and by its Arabic language acronym Daesh (Arabic: داعش‎ ‎ "dāʿish", ] ), is a Salafi jihadist militant group and unrecognised proto-state that follows a fundamentalist, Wahhabi doctrine of Sunni Islam.
 ISIL gained global prominence in early 2014 when it drove Iraqi government forces out of key cities in its Western Iraq offensive, followed by its capture of Mosul and the Sinjar massacre.
Abu Musab al-Zarqawi (Arabic: أبو مصعب الزرقاوي‎ ‎ , "’Abū Muṣ‘ab az-Zarqāwī ", "Abu Musab from Zarqa";    ; October 20, 1966 – June 7, 2006), born Ahmad Fadeel al-Nazal al-Khalayleh (أحمد فضيل النزال الخلايلة , "’Aḥmad Faḍīl an-Nazāl al-Ḫalāyla "), was a Jordanian jihadist who ran a paramilitary training camp in Afghanistan.
 He became known after going to Iraq and being responsible for a series of bombings, beheadings, and attacks during the Iraq War, reportedly "turning an insurgency against US troops" in Iraq "into a Shia-Sunni civil war".
 He was sometimes known as "Shaykh of the slaughterers".
Abu Muhammad al-Maqdisi (Arabic: أبو محمد المقدسي‎ ‎ ), or more fully Abu Muhammad Essam al-Maqdisi (‎ أبو محمد عصام المقدسي), is the assumed name of Essam Muhammad Tahir al-Barqawi (‎ عصام محمد طاهر البرقاوي), an Islamist Jordanian-Palestinian writer.
 He is best known as the spiritual mentor of Jordanian jihadist Abu Musab al-Zarqawi, the initial leader of al-Qaeda in Iraq.
 However, an ideological and methodical split emerged between Maqdisi and Zarqawi in 2004 due to Zarqawi's takfeer proclamations towards the Shia populations in Iraq.
 Maqdisi opted for a more cautious approach towards targeted Shia killings, attempting to stop Zarqawi's radical ideological movement before Zarqawi's methods become counter-productive.
Ahmad Musa Jibril (alt.
 Jebril, born 1972), also known as Abu Khaled, is a Palestinian-American Islamic preacher, cleric, sheikh, and imam.
 In 2004 he was convicted on 42 charges including arson and fraud.
 He promotes Salafist militant Islamism, and has extensively preached about Syrian Civil War in highly emotive pro-Sunni terms.
 While not known to be affiliated directly to any particular group, it has been claimed that he has been an inspirational source for many English speaking pro-Sunni jihadist fighters in Syria, in both al-Nusra and Islamic State of Iraq and the Levant, and elsewhere.
On August 1, 2004, a series of car bomb attacks took place during the Sunday evening Mass in churches of two Iraqi cities, Baghdad and Mosul.
 The six attacks killed at least 12 people and wounded at least 71.
 No one claimed responsibility for the attacks, but Iraq's national security adviser, Mowaffaq al-Rubaie, blamed the attacks on Abu Musab al-Zarqawi.
 The bombings marked the first major attack against the Christian community since the 2003 invasion of Iraq.

Question: The Jordanian jihadist who was also known as the "Shaykh of the slaughterers" was blamed for the deaths of how many during the 2004 Iraq churches attack in 2004?
Answer: 12