TOP AIDES IN LAOS FORCED TO RESIGN
Pol scene in Vientiane described as many top right-wing officials of coalition Govt resign under pressure from demonstrators; Govt orders 20 bars and nightclubs in capital to close on July 1; Lao press releases say Vientiane Mayor Phagna Sisouvan resigned after demonstrators barricaded city hall to demand ouster of Sisouvan and 4 deputies; fate of deputies has not been decided; sr econ delegation reptldly leaves for Peking to discuss China's financial aid program for Laos; delegation will stop in Hanoi enroute to Peking to negotiate problem of 'transit of merchandise' provided by China (M)