WASHINGTON - The United States on Monday confirmed the death of the Islamic State's senior leader in Libya, known as Abu Nabil, who was targeted in a Nov. 13 US air strike carried out by F-15 aircraft on a compound in the city of Derna. Pentagon spokesman Captain Jeff Davis also confirmed that a senior leader of the al-Qaida-affiliated group al Shabaab was killed in a US military air strike in Somalia carried out on Dec. 2. The Pentagon named him as Abdirahman Sandhere, also known as 'Ukash,' and said the strike represented a significant blow to the group.