U.S. and coalition airstrikes killed 10 Islamic State leaders over the past month, including several linked to the Paris attacks or other plots against the West, a U.S. military official in Iraq said Tuesday.

U.S. Army Col. Steve Warren told Pentagon reporters that the jihadists were killed mainly by drone strikes in Iraq and Syria. He offered few details, but said at least two of those killed were linked to the Paris attacks.

According to Warren, one of the insurgents killed was Charaffe al Mouadan, a Syrian-based ISIS member who was directly linked to Abdel Hamid Abaaoud, the Paris attack cell leader. Mouadan, who was killed by an airstrike last Thursday in Syria, was planning additional attacks against the West, Warren said.

Also killed was Abdel Kader Hakim, who was part of ISIS efforts to plan attacks against Western targets and "had links" to the Paris attack network, Warren said.

Most of the 10 appeared to be mid-level leaders.

Warren's announcement came as Belgian authorities announced they had arrested two men in connection with a suspected plot involving attacks during the holiday season in Brussels. They said the plans involved attacks similar to those that hit Paris on Nov. 13, when 130 people were killed and hundreds more wounded by suicide bombers and gunmen. The Islamic State group has claimed responsibility for the Paris attacks.

Ramping up pressure

The U.S. is ramping up pressure on such high-value militants. Earlier this month, President Barack Obama announced he is sending U.S. special operations forces into Iraq to conduct clandestine raids targeting Islamic State group leaders. The commandos — likely about 100 — would operate in small teams, gathering intelligence that will fuel airstrikes and other operations.

So far, the Pentagon has not said when the special operations forces will deploy.

"We're striking at the head of this snake," Warren said. "We haven't severed the head of the snake yet, and it's still got fangs. We have to be clear about that. There's much more fighting to do."