as missing in action, rne communists staged mortar barrages on two 9th Infantry Division posts, one a battalion base carnp.otI1icsVtAlmost simultaneously, the Vietcong fired mortar shells into the headquarters of the Quang Dien district, killing the district chief and five South Vietnamese militiamen. Twenty other militiamen were wounded.In the air war, U.S. Air Force B52 jets rained tons of bombs early today on Communist fortifications 39 miles southwest of Kontum city on the central highlands in support of Operation Sam Houston.ctrtl:aEOver North Vietnam yesterday, clouds and rain limited the]]linumber of missions, but some*strikes were carried despite the weather.ct;U.S. Air Force F4C Phantom and F105 Thunderchief jets raided storage areas, bridges, roads and trucks west of Hanoi and east of Dien Bien Phil. Navy pilots reported destroying two barges and damaging 19 others.rErNorth of the zone, along the North Vietnamese coast. Com-1 \ munist resistance appeared to 1cbe stiffening to U.S. naval bombardments directed against key coastal shipping routes in NorthiVietnam.Three American vessels, the guided missile cruiser Canberra and the destroyers Kep-pler and Ingersoil, were fired on by Communist batteries on the island of Hon En, 41 miles south-southeast of Vinh as they swept along the coast.The U.S. ships escaped being hit, and turned their own guns on the attackers.