Necessary friction?

This is from today's Lebanese Daily Star:

Israel reported Monday that it had moved to bolster a fragile cease-fire with Palestinians by ordering its troops in the occupied West Bank to avoid "unnecessary friction" as the truce entered its ninth day. Despite the announcement, Israeli troops shot dead a Palestinian civilian on Monday during a raid in the West Bank city of Tulkarem to arrest a militant, who was wounded along with a teenage bystander in the incident, Palestinian security sources said.

Killing civilians seems to be a necessary friction then.