Start here: The fight against ISIS on Friday

Willie Grace | 2/20/2015, 8:03 a.m. | Updated on 2/20/2015, 8:03 a.m.
Up to 25,000 Iraqi troops: An Iraqi ground offensive to push ISIS out of Mosul is now expected to begin ...

(CNN) -- An Iraqi operation to retake Mosul from ISIS could begin this spring. A Minnesota man is charged with trying to join the terrorists. And President Barack Obama wants to deny the militants legitimacy.

Here's the latest on the jihadist group and the global efforts to stop it:

THE MOSUL ATTACK PLAN

Up to 25,000 Iraqi troops: An Iraqi ground offensive to push ISIS out of Mosul is now expected to begin in April or May, a U.S. military official said Thursday. Up to 25,000 Iraqi troops could be involved, the official said. The attack will include five Iraqi army brigades that will be trained by the United States and Peshmerga, or Kurdish, forces that will try to cut off any ISIS escape routes north and west of the city, the official said. ISIS seized Mosul, Iraq's second largest city, in June. There's one big question lingering: What role, if any, could U.S. troops play on the ground as Iraqi forces try to retake it?

THE THREAT

Minnesota arrest: Federal authorities on Thursday charged a 19-year-old Minnesota man on suspicion of trying to travel to Syria to join ISIS. Hamza Naj Ahmed, charged with attempting to provide material support to ISIS, is accused of traveling to New York's John F. Kennedy International Airport with the intent of flying to Istanbul, Turkey, in November. Investigators were tracking him because he was communicating with a Minneapolis man who has been overseas and is suspected of extremist ties, a federal law enforcement official familiar with the probe said. In other recent cases, authorities have arrested an Illinois teenager and three Colorado teenage girls, accusing them of attempting to travel to the Mideast to join ISIS.

Turkish warning: Turkey's intelligence agency has warned police that ISIS members may be planning attacks in Ankara and Istanbul against the diplomatic missions of countries in the U.S.-led coalition, the national newspaper Hurriyet reported. Militants have crossed into Turkey after retreating from the Syrian city of Kobani, the warning by the National Intelligence Organization reportedly said. CNN is trying independently to confirm the account.

THE BRUTALITY

Burned alive: Every few days, it seems as though ISIS ups the ante on its savagery. Wednesday brought news that the militants killed at least 40 police officers and tribesmen in a town they recently seized in Iraq's Anbar province -- and that most of the victims were burned to death. That's according to an Iraqi official. CNN hasn't independently confirmed the account. The Pentagon says it's looking into it.

Harvesting organs: Iraq's U.N. ambassador says his country has asked the United Nations to look into another shocking allegation -- that ISIS is harvesting organs from slain civilians and selling the body parts. Britain's ambassador to the United Nations, Mark Lyall Grant, said there was no proof or evidence of the claim.

THE COUNTEROFFENSIVE

End the embargo: ISIS is metastasizing at warp speed in Libya. The killings of 21 Egyptian Christians in Libya highlight how the group is taking advantage of the collapsing state. Now Libya is asking that a U.N.-imposed arms embargo be lifted so it can better fight the threat.

Kill list: The United States is maintaining a list of about two dozen top ISIS operatives in Iraq and Syria that it hopes to target in airstrikes, a senior U.S. official said. No. 1 on the list? ISIS leader Abu Bakr al-Baghdadi.

THE SUMMIT

Denying legitimacy: The United States is not at war with Islam but with "people who have perverted Islam," Obama said Wednesday at his three-day Summit on Countering Violent Extremism. The White House has gone out of its way not to name Islamic extremism as the summit's central focus. Obama explained why. Groups such as ISIS, he said, are "desperate for legitimacy."

THE PROPAGANDA

Speech analysis: Just as it's doing with "Jihadi John," the intelligence community is trying to figure out the identity of the new English-speaking killer in the video ISIS released showing the beheadings of the Egyptian Christians. The most intriguing clue is in his voice: The accent appears to be either American or Canadian.

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