igonirfieldsRaked byFireSAIGON (API —Communist rockets and mortars raked twoairfields near Saigon today, kill*ing six Americans, wounding 100 and destroying or damaging 25 planes.Far to the north, two U.S. Marine positions just below the demiliarized zone came under enemy aarrages. These were at Gio Linh and Con Thein, where Leathernecks and Army artillerymen join to counter enemy threats from across the demilitarized zone.AP correspondent Peter Arnett reported from the scene that Gio Linh was hit by from 10 to 15 rounds of mortar or artillery' fire hourly all through the afternoon. One explosion set offa fire among a stack of white ’ phosphorus shells. The blaze was brought under control after one hour.The number of casualties at Con Thien, seven miles west of Gio Linh, was undetermined. Helicopters made 24 medical evacuation flights from that outpost.A dispatch from the Marine headquarters at Da Nang said one enemy shell hit a Marine helicopter flying between Gio Linh and Dong Ha, eight miles to the south, and four Marines were injured.The guerrillas used the biggest weapon in their arsenal, their Soviet 140mm rockets,against the big airbase at Bien Hoa, 16 miles northeast of Saigon.U.S. officers speculated that the attacks on the airfields were in ,-eply to the U.S. raids on MIG airfields near Hanoi which began last month.The two fields hit were Bien Hoa, the largest tactical fighter base in South Vietnam, and an Army airstrip at Phuoc Vinh. 34 mi lee north of Saigon. Phuoc Vinh is largely a support strip, with helicopters, transport aircraft and spotter planes stationed there.School Board Receives BidsFor Junior High CafeteriaSchool District 413 Board of Education accepted bids yesterday for construction of a cafeteria on the campus grounds of Rovster Junior High School on West Main.Low bidder was the N. F. English Construction Co. who is the present contractor for the new junior high buildings. TheFriends Universitybid was 572.549.Sell Construction Co. of Iola was next low bidder at $74,100.The Board of Education is now negotiating with English and a contract is expected to be awarded soon at a figure some $4,000 under the bid. Supt. Buford Fisher said today that an agreement should be reached and a contract awarded by the first of next week.The building will be locatedIn addition to the six killed and 100 wounded. U.S. head-quaiters said about 30 more Americans received such minor injuries as sprained ankles as they sprinted for cover.Tlie U.S. Command said damage to the airfields was light to moderate and gave no furtherbreakdown. However, eyewitnesses reported at least 25 planes damaged at Bien Hoa and more were known to have been shot up at Phuoc Vinh.Elsewhere in South Vietnam, only light ground fighting was reported. Bad weather continued to hamper raids over the North, but 135 missions were flown Thursday, mostly against supply targets in the lower halfof North Vietnam.tfLt