Four U.S. troops were wounded in a helicopter raid in Syria that killed a senior ISIS leader on Thursday night, according to the U.S. military.The U.S. troops, as well as a working dog, were wounded during the raid when there was an "explosion," U.S. Central Command said in a statement. The raid killed Hamza al-Homsi, a senior ISIS leader.Officials told CNN that U.S. forces were "close to" al-Homsi when the explosion happened, killing al-Homsi and wounding the U.S. service members. It is unclear at this point if the explosion was the result of a suicide vest, a booby trap, or something else, two officials said.Three of the service members are in stable condition, according to another military official familiar with the operation, as is the working dog. The fourth service member suffered minor injuries and has returned to duty, the official said.Three of the troops and the dog are currently receiving treatment in a medical facility in Iraq. The U.S. service members may be transported to the military hospital in Landstuhl, Germany, for further treatment, according to the two officials.The joint raid was carried out by U.S. and Syrian Democratic Forces, said CENTCOM.No Syrian Democratic Forces (SDF) troops were injured in the raid, the two officials told CNN.CENTCOM also announced in a tweet that a separate raid on February 10 killed "Ibrahim Al Qahtani, an ISIS official associated with planning ISIS detention center attacks."The raid also "resulted in the seizure of multiple weapons, ammo, and a suicide belt," according to the tweet.Two other ISIS leaders were killed in Syria in October last year, when the U.S. carried out an airstrike in northern Syria. The strike killed Abu 'Ala, ISIS' deputy leader in Syria and one of the terror group's top five leaders, as well as Abu Mu'Ad al-Qahtani, an ISIS leader in charge of prisoner affairs.Another senior ISIS leader, Bilal al-Sudani, was killed just last month in a U.S. military operation in Somalia.