May 9, 1981

With tensions running high after the assassinations of seven military men and Civil Guards in less than a week, Prime Minister Leopoldo Calvo Sotelo tonight accused unidentified foreign states of fomenting terrorism in Spain. In a television address to the country, the Prime Minister promised a ''long and hard struggle'' against terrorism, though he announced no new measures. At the outset of his talk, Mr. Calvo Sotelo, who heads a centerright Government, affirmed that ''terrorism in Spain cannot be understood only in terms of its internal traits, but also must be seen in the field of international action.''

Two children were fatally crushed yesterday morning by a 12-wheel tractor trailer as their mother was walking them and their baby brother across Seventh Avenue South opposite St. Vincent's Hospital on 11th Street. The crosswalk is part of a busy six-street intersection in Greenwich Village where traffic is usually heavy. The parents of children at nearby Public School 41 say they have been demanding a crossing guard for the intersection since September. According to the police and witnesses, the mother, Fatima Delosevic, and her three children began crossing the avenue from west to east at about 10:15 A.M.The truck, headed south on Seventh Avenue, had stopped for a red light. When it started again, it ran over the two older children, nearly crushed a baby carriage and caught one of the mother's shoes under a wheel before coming to a halt.

Syria today formally rejected Israeli demands for withdrawal of antiaircraft missiles from Lebanon as Philip C. Habib, the special American envoy, began discussions here on easing the crisis. ''Air defenses, including missiles, are part of Syria's armed forces,'' said a statement issued in Damascus by the Syrian Defense Ministry. ''They exist now, and will in the future, wherever Syrian troops are, when they need them.''

The Metropolitan Transportation Authority yesterday rejected a proposal that would have barred the use of air-conditioning on New York City buses unless the outdoor temperature exceeded 90 degrees. It said it would continue to leave such decisions ''to the discretion of the drivers.'' But some bus drivers may not have much of a choice. John D. Simpson, president of the New York City Transit Authority, said that on ''at least 2,200'' - or three-quarters - of the system's 2,700 buses equipped with air-conditioning, the equipment was not working at this time.

The Senate reversed itself today and voted, 49 to 42, to recommend a $7.9 billion reduction in cost-of-living increases for Social Security recipients and retired Federal employees in the fiscal year 1982. The saving would occur because of a change in the method of calculating increases in retirement benefits based on inflation. The Senate Budget Committee had recommended, and the Senate agreed today, that the increases should be based on either the Consumer Price Index or the national average increase in wages, whichever was lower, rather than solely on the price index. The Congressional Budget Office feels that the Consumer Price Index, because of the factors that go into its calculation, shows an unrealistically high rate of inflation. In recent years average wage increases have been lower than the cost-of-living increase as measured by the Consumer Price Index. The effect of today's vote to use the wage standard in calculating retirement benefits, combined with a proposed three-month delay next year in the date for the costof-living adjustment for retired Federal employees, would lead to an estimated saving of $7.9 billion next year.