washington u.s. lawmaker urge obama administration suspend cooperation saudi-led coalition conduct airstrikes yemen say letter release wednesday civilian casualties strike appear result war crimes rep. ted lieu california democrat write secretary state john kerry tuesday say coalition conduct 70 unlawful airstrikes yemen appear either saudi coalition intentionally target civilians distinguish civilians military target would war crimes write lieu teach class law war lawyer u.s. air force letter increase pressure white house yemen administration announce saturday review support saudi-led coalition air strike kill 140 mourners funeral u.s. arm sales riyadh support coalition halt white house review complete lieu write lieu also cite reuters article publish monday report obama administration go ahead arm sales saudi arabia despite officials fear washington could implicate war crimes support saudi-led air campaign saudi-led coalition say take responsibilities international humanitarian law seriously commit protection civilians yemen state department spokesman john kirby say statement wednesday receive letter aware congressional concern regard arm sales saudi arabia remain gravely concern high toll conflict include civilian casualties damage infrastructure cause side conflict aid assistance country always review subject modification go review position continue policy discussions kirby say several recent efforts u.s. congress halt arm sales saudi arabia fail white house saturday announce initiate immediate review u.s. support saudi-led coalition apparent coalition air strike funeral saudi arabia say investigate circumstances strike u.s. lawmaker urge saudi arm sales halt cite possible yemen 'war crimes