Israeli army units reappeared in Nablus on the West Bank in the small hours today to arrest Palestinian terrorists. Israeli soldiers have previously re-entered Qalkiliya and Tulkarm. Operation Protective Wall has spread to all Palestinian towns along the West Bank except Jericho. Analysts ascribe resumed action to demands of secret services as arrested Palestinians inform them about ever more terror-involved persons at large. There are Israeli reports of several HAMAS militants arrested in villages near Hebron and Qalkiliya in the small hours today. Whatever Israel may be claiming, Operation Protective Wall is still underway, point out analysts. Israeli army units are not withdrawing to previous positions or, if they do, they remain stationed in the environs to keep Palestinian towns encircled. Tensions persist in the Gaza strip, though it is not yet involved in the operation. Several Jewish settlements near Rafiyah in the strip's south were under mortar fire last night into Friday morning.