Complex sentence: The US military claimed the people targeted were militants belonging to the terrorist group al-Qaeda, however the Syrian Observatory for Human Rights (SOHR), local residents and local officials have claimed that the building struck was a mosque filled with worshipers.
Split into simpler sentences: The US military claimed the people targeted were militants belonging to the terrorist group al-Qaeda. However, the Syrian Observatory for Human Rights (SOHR), local residents and local officials have claimed that the building struck was a mosque filled with worshipers.