Al-Qaida-affiliated groups are redeploying their resources in rebel-held parts of Syria amid widespread fears that any strikes carried out by the U.S. would target not only the Syrian government but also Islamists in the opposition, according to rebels.

In many parts of the northern and eastern provinces that have fallen almost entirely under rebel control, extremist groups have been evacuating headquarters, moving military equipment and, in some instances, fleeing to what is considered safer ground in mountainous terrain. The moves mirror preparations by forces loyal to President Bashar Assad, which are in the process of shifting troops and armor out of major military facilities and into schools and residential neighborhoods, witnesses say.

The White House stressed last week that a decision to attack Syria has not yet been made. The U.S. has also given no indication that any of the extremist groups in the Syrian opposition would be on its list of targets, even though two key groups are designated terrorist organizations — Jabhat al-Nusra and the Islamic State of Iraq and the Levant, which has expanded into Syria from Iraq.