Iraqi special forces charged into the Mosul battle Thursday with a pre-dawn advance on a nearby town held by the Islamic State group, a key part of a multi-pronged assault on eastern approaches to the besieged city.

Here is a look at key developments on the fourth day of the Mosul offensive:

A MULTI-PRONGED OFFENSIVE

The special forces backed by attack helicopters fought their way into the town of Bartella, where IS militants unleashed at least nine suicide truck bombs. Lt. Gen. Talib Shaghati said the special forces retook Bartella, about 15 kilometers (nine miles) from the edge of Mosul. But Iraqi forces were facing stiff resistance inside the town shortly before he spoke.

The U.S. trained special forces are Iraq's most highly trained and least sectarian fighters, and will lead the charge into Mosul.

Kurdish peshmerga forces also announced a "large-scale operation," and peshmerga forces stationed on mountains northeast of Mosul descended from their positions and charged toward the front line. Military operations also appeared to be underway in the town of Bashiqa, northeast of Mosul, which was pounded by airstrikes and peshmerga mortars the day before.

More than 25,000 forces, including the Iraqi army, the peshmerga, Sunni tribal fighters and Shiite militias are taking part in the Mosul offensive, which began Monday after months of preparation. They will be advancing on the city from several directions.

IRAQ CITES PROGRESS

Iraqi Prime Minister Haider al-Abadi, speaking by video link to diplomats meeting in Paris, said the Mosul offensive was moving "more quickly than we thought." He vowed to protect fleeing civilians and said the government "will not allow any violations of human rights."

He was speaking by video link to a Paris conference, where diplomats from the U.S., Iraq and some 20 other countries gathered to devise a plan to protect civilians, distribute aid and address questions about governing areas newly liberated from IS.

The Islamic State group captured Mosul and the surrounding area during a lightning advance across northern Iraq in 2014, and IS leader Abu Bakr al-Baghdadi announced the formation of a self-styled caliphate from the pulpit of a Mosul mosque. Mosul is the largest city controlled by the extremists and their last major urban bastion in Iraq.