POWELL SAYS SYRIA IS TAKING ACTION ON TERROR GROUPS
Sec of State Colin L Powell meets with Pres Bashar al-Assad in Damascus and says Syria has begun closing offices of at least some militant anti-Israeli groups in Damascus as demanded by US; groups are identified as Hamas, Popular Front for Liberation of Palestine-General Command and Palestinian Islamic Jihad; closings appear to be breakthrough in dealing with Syria, which has had an up-and-down relationship with US over years and more recently has been labeled by some American officials as junior member of 'axis of evil' because of its tolerance of groups' presence; Powell also demands that Syria turn over any Iraqi leaders hiding in Syria and ensure that no weapons are flowing from Syria into Iraq now that American occupation is encountering some attacks in parts of country; also expresses concern about Syrian support for Hezbollah, Shiite group that is active in Lebanon and has lobbed missiles into Israel; photo (M)