Start here: The fight against ISIS on Friday

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?

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.

CNN’s Richard Roth, Jim Acosta, Sarah El Sirgany, Tim Lister, Jim Sciutto, Barbara Starr, Jomana Karadsheh, Salma Abdelaziz, Atika Shubert, Evan Perez, Shimon Prokupecz and Catherine E. Shoichet contributed to this report.

CNN