ISIS has advanced from Mosul, which it seized on June 10, to take control of Tikrit, the capital of Salah ad-Din Province, Baiji, and the Baiji oil refinery. As of June 11, 2013, ISIS forces have also fought the ISF in Abu Ghraib and Zaidan west of Baghdad, further demonstrating the group’s capacity to manage simultaneous operations by multiple subordinate commands. Unconfirmed reports indicate that ISIS also conducted a second attack on Samarra, where retreating ISF forces from Tikrit have reportedly concentrated. ISW cannot assess the degree to which ISIS has moved to control the town of Samarra or to attack the al-Askari shrine as of 2300 EDT.

ISIS operations around Samarra during this phase of its northern offensive will be an important indicator of its ultimate intent and its estimate of its own capabilities. If ISIS means to continue a blitzkrieg offensive toward Baghdad it will likely need to bypass Samarra to maintain momentum and conserve forces. But Samarra is extremely significant in itself. Al-Qaeda in Iraq’s destruction of the al-Askari Shrine in 2006 ignited the sectarian civil war that had been simmering before then. Prime Minister Nouri al-Maliki will surely feel a great deal of pressure to prevent a repetition of such an event and may well attempt to concentrate forces to prevent it. Iraqi forces, militias, and Iranian proxies have long been in Samarra precisely to protect the shrine. ISIS could therefore attack the shrine for any of several reasons. It could seek to draw the ISF into a meeting engagement in hopes of defeating arriving ISF troops piecemeal. It could intend to destroy the rebuilt shrine to inflame the sectarian war even further. It could even find irresistible the prospect of fighting the actual Iranian forces and proxies thought to be in the city. Any or all of these conditions could lead to a major battle in Samarra, or the ISIS command might instead decide to bypass the shrine and continue south.

ISIS leaders might also believe that they have sufficiently disrupted and softened-up ISF and militia forces in Samarra to make an attack relatively easy. ISIS has been testing the Iraqi Security Forces and municipal buildings, of Samarra since mid-March through VBIED attacks, complex attacks, IEDs, and driving armed vehicles through the city. ISIS also burned thousands of acres of crops in the vicinity in May. The previous ISIS attack on Samarra on June 5, 2014, which preceded the northern offensive for Mosul, may also have been intended to disrupt Samarra’s defenses in advance of the arrival of the main body from the north.

Still another reason why ISIS might conduct additional attacks on Samarra could be in order to divert ISF attention from other operations. A major fight in Samarra risks bogging ISIS down and causing its advance to culminate prematurely – unless it has operational reinforcements.

But ISIS may very well have operational reinforcements. Fallujah and Jurf as-Sukhar, its strongpoints in Anbar and Babil, have been relatively quiet since the widespread ISIS operations began on June 5. Therefore, ISIS could be attacking Samarra in order to draw ISF and reinforcements there, while maneuvering from the Anbar or Babil axis of advance (or both) toward Baghdad. VBIED attacks against Sadr City and Khadimiya (home to another important Shi’a shrine) could be diversions, tests, or efforts to soften up the defenses in Baghdad.

It appears so far that ISIS is pursuing a well-planned and well-prepared deliberate offensive operation, rather than simply exploiting the collapse of the ISF in Mosul in a pell-mell advance. We have seen that ISIS has the capability to plan and conduct complex operations before. We must consider and be prepared for the possibility that additional ISIS attacks will unfold over the next 96 hours with the aim of completely disrupting and unhinging the ISF, even if ISIS is unlikely to be able to seize and hold Baghdad.

ISIS has never launched an offensive this expansive in Iraq. It is very possible that it could fall prey to the over-exuberance normal for a military seeing success beyond its dreams. ISIS could be over-extending itself, in that case, making it vulnerable to rapid counter-offensives or even to the rise of angry citizenry in its rear areas—a phenomenon that we have already begun to see to some extent in Mosul and that is well-known in ISIS’s main Syrian base in ar-Raqqa. But ISIS has also conducted sophisticated, multi-phased maneuver campaigns in Deir ez-Zour, Syria, showing its capability of integrating deception operations with movement in order to seize its objectives.

The most important question we must answer to understand whether ISIS is pursuing a well-laid plan or is pushing its luck too far is whether the same ISIS forces are moving from location to location, or are prepositioned forces being activated for simultaneous advance? This question is critical to understand the size and composition of ISIS’ force involved in the northern campaign. Reflections from the ground indicate that ISIS attacked Mosul with 150 vehicles armed with mounted crew-served weapons and between 500 and 800 troops. It is unclear if elements of this same force moved on to take Sharqat, Qaiyara, Baiji, and Tikrit, or if separate forces already proximate to these locations simply moved in to take their respective targets in sequence. ISW is actively searching for indicators of how ISIS attacked and seized control of these cities in order to answer this question. If ISIS had pre-positioned forces, then these forces likely now occupy their current target zones, which would allow the ISIS advance to continue.

If instead ISIS is seizing a city and establishing a leave-behind force while the assault force maneuvers, then the offensive is likely to culminate before it reaches Baghdad, depending on the nature of the force left behind. Is ISIS forming relationships with local tribes to help hold their newly acquired cities? Are recently released prisoners with little training part of that force? To what extent has ISIS made common cause with the Ba‘athist forces under former Saddam General Izzat Ibrahim al-Douri and the Jaysh Rijal al-Tariqa al-Naqshabandia (JRTN)? Reports indicate that JRTN forces and al-Douri supporters are active in Mosul and Tikrit, but we are not able to assess the extent of this activity with any confidence at this point.

It should be possible to assess in the next 24-48 hours whether the current ISIS offensive will continue uninterrupted or whether there will instead be a pause while ISIS regroups and consolidates. The level of activity in the areas northwest and southwest of Baghdad will likely be the most important indicator to watch.

Significant Events June 11, 2014 Mosul: In western Mosul, ISIS gunmen reportedly used IEDs to destroy the Badush Bridge along the road to Dohuk, allegedly in an effort to ward off potential Peshmerga deployments. Additionally, the bodies of 17 civilians executed by ISIS were reportedly found on the eastern side of Mosul. The identity of the victims was not confirmed, but they were likely members of security forces or anti-ISIS elements executed as a retaliatory measure by ISIS.

According to Ninewa Governor Atheel Nujaifi, ISIS distributed large amounts of money from the Mosul branch of the Central Bank to civilians. This is most likely an effort to win over public opinion, securing their gains in the city.

The head of the Ninewa security committee, Bashar al-Kiki, announced that ISIS militants stormed the Turkish consulate in Jawasaq, located in south Mosul, and took hostage the Turkish Consul Ozturk Yilmaz, and 41 other consulate employees. In response, UN Secretary-General Ban Ki-Moon condemned the kidnappings, calling the action “totally unacceptable,” and urged the Iraqi government and the international community to do everything possible to ensure the safe return of the diplomats. The Turkish Ministry of Foreign Affairs also released a press statement.

Tribes in Ninewa claim that they have “liberated” the Mosul neighborhood of al-Wahda from ISIS militants, killing 23 ISIS members. While limited, this effort could signal some local resistance to the ISIS incursion. Many residents of Mosul seem to believe that ISIS does not in fact have full control of the city and that “members of Saddam’s former army” are present. This may be a reference to the Ba‘athist Jaysh Rijal al-Tariqa al-Naqshabandia (JRTN), which former CoR member Mishaan al-Juburi described as involved in overtaking Tikrit. There are also rumors that Izzat Ibrahim al-Douri, a senior member of Hussein’s inner circle, is now commanding the rebel elements in Mosul. Given al-Douri’s position in JRTN, this rumor is intended to signal the significance of Mosul to the group.

Ninewa: Major General Abd al-Rahman Korini, a Peshmerga commander, stated that Peshmerga forces killed five ISIS militants and destroyed 20 ISIS vehicles in the Sanoon area near Sinjar in western Ninewa.

Samarra: This afternoon, clashes were reported between ISIS and ISF at the entrance to Samarra, and later at the “fortified” area that contains the al-Askari Shi’a Shrine. According to security sources, General Ali al-Furaiji and General Hatem al-Magsusi have been assigned to command military operations in Salah ad-Din province. Command and control of operations in the province are orchestrated from Samarra.

Baiji: ISIS took control of Baiji. According to an anonymous security source, ISIS released 70 prisoners from a police station in Baiji after taking it over earlier in the day. ISIS has also reportedly taken control of the North Oil Company in Baiji, which is located in northern Salah ad-Din.

Tikrit: ISIS reportedly attacked Tikrit from the north, east, and west sides of the city. As of the morning of June 11, ISIS appears to have had full control of Tikrit. ISIS militants reportedly seized the Salah ad-Din provincial council, and set the provincial government building on fire.

Gunmen captured the village of Auja, after engaging in clashes with the ISF that resulted in the deaths of the commander of the Fourth Division of the IA, Major General Nazir Assem, and five other soldiers. The commander had been stationed in Tikrit, but withdrew to Auja along with guards after armed groups captured the city. Auja is significant as the hometown of former Iraqi president Saddam Hussein.

Kirkuk: Reports of anti-ISIS tribal mobilization near Hawija, west of the city of Kirkuk, on the morning of June 11th, failed to materialize. According to the commander of the Peshmerga 2nd Brigade declared that all Tigris Operation Command units deserted in Kirkuk. Fifteen ISF members were reportedly killed by ISIS in the process of fleeing Kirkuk.

ISIS militants wearing military uniforms reportedly established checkpoints in the Riad areas, 45 km west of Kirkuk, and near the entrance to Rashad, south of Kirkuk.

Members of the 12th Division have fled their position at Camp K-1 near Kirkuk, according to an anonymous officer from the division, although the unit’s commander, Major General Mohammed Khalaf Said al-Dulaimi, remained in Kirkuk.

As a show of solidarity, leaders of the Kurdish parliamentary blocs in Iraq’s parliament arrived in Kirkuk. A delegation from the Kurdistan Regional Government (KRG), led by the head of the parliament of the KRG, Yusuf Mohammed Sadiq, met with the governor of the province, Najm ad-Din Karim, and subsequently stated that the visit was important because “[Kirkuk] is a part of the Kurdistan region.”

Four Peshmerga soldiers were also injured in clashes between Peshmerga and IA forces. The anonymous security source stated that IA forces accidentally fired on Peshmerga soldiers in the Qadr Karm area as they withdrew forces from Salman Beg to Kirkuk.

Baghdad: On June 11th, 16 killed and 34 wounded in a suicide bombing targeting a funeral in Sadr City, Baghdad. A VBIED also exploded at the entrance to the al-Khadhimiya neighborhood in central Baghdad. VBIEDs are the signature attack of ISIS, indicating that these attacks were likely carried out by the organization. ISIS also claimed to have detonated three explosives in Tarmiyah, allegedly destroying the houses of senior ISF officers and a Sahwa leader. This is likely part of an information operation to intimidate members of the security forces.

Baghdad Operations Command has imposed a curfew on Baghdad between 22:00 and 6:00. Such curfews are rare in Baghdad, and likely indicate that the government is anticipating an attack on the city.

On the morning of the 11th, ISIS reportedly took control of an army headquarters in northern Dhuluiya (100 km north of Baghdad). ISIS militants were seen taking the weapons of fleeing ISF members. Later in the day, ISIS forces were seen in the city of Balad, located north of Dhuluiya and 30 km south of Samarra.

Babil: The director of a Tribal Council in Babil, Brigadier General Mohammed al-Awadi, stated that 2000 volunteers from 19 tribes offered their support to ISF forces in Babil, Diyala, and Mosul and those volunteers will reportedly begin training on June 12. The Governor of Babil, Sadiq al-Sultani, has stated that the government is accepting volunteers from tribal communities to assist in providing security to holy sites.

Southern regions: According to an anonymous police source, a Suicide Vehicle-Borne Improvised Explosive Device (SVBIED) exploded in a popular market in Safwan, a village southwest of Basra and near the Kuwaiti border. The explosion killed 10 civilians and wounded 10 others. A VBIED also exploded in a parking garage in the al-Khanasa area in Karbala, killing five civilians and wounding four others, while a second VBIED exploded outside the municipal court in the Nu’amaniya area in Wasit Province, injuring 14 civilians.