Washington, Nov. 24: On the basis of reports from its own Intelligence channels the U.S. is understood to have concluded that regular units of the Indian Army have moved into East Bengal during the last 48 hours. Official sources here admit that Pakistani allegations that a full-scale attack by 12 or more Indian divisions is a gross exaggeration. Their estimate rather is that two or three Indian brigades have moved into East Bengal in Jesore sector to support a Mukti Bahini offensive. These officials are therefore not accepting Indian denials of absolute non-involvement in the fighting that has flared up in East Bengal. The U.S. assessment therefore is that while the present situation is far short of war, the prospect of such a conflict is now much nearer. Washington is therefore watching the situation to see how it develops before adopting any particular course of action. This is evident from the fact that neither the State Department nor the White House has until now called in either the Indian or Pakistani envoys here to express their concern — calls to the two countries to cool have so far only emanated from press spokesmen of the U.S. Government.