On the eve of the crucial fourth round of talks between key interlocutors of the two countries next week, sources say the atmosphere is beginning to sour over aggravating US actions.

Following up on the virtual expulsion of several Indian scientists last month, the Clinton administration has directed some more to leave. The latest victims are scientists on short-term assignments to Chicago's Enrico Fermi Institute and Argonne National Laboratory.

Compounding the expulsions, the administration has now decided to hold back high-tech Indian test equipment related to the Light Combat Aircraft project sent by Bangalore's Aeronautical Development. The equipment, two Engineering Test Stations were sent toLockheed Martin facility in Binghampton in upstate New York to test the US-made Digital Flight Control Computers (DFCC) under an MoU. But following the May nuclear tests and the sanctions which followed, the administration is blocking the return of the Indian ETS saying it is sequestered under the Glenn Amendment, despite requests from the Indian side for its return. Officials in India say the ETS were sent to US with an import certificate and a re-export license. Other sources said some equipment sent by the Indian Navy to the US for repairs had also been seized.

Indian officials are nonplussed by the US attitude because from all accounts the two sides are having cordial talks that appear close to being fruitful. Key Indian officials said they would point out the inconsistencies in the US position and ``errors of application'' but there would be no supplicating.

``They appear to think even holding back Indian equipment falls under the purview of the Glenn Amendment. We disagree,'' a key Indian diplomatsaid. The matter is expected to figure in the Talbott-Singh talks.

Other Indian officials said the sending back of Indian scientists was a private matter since most of the Indian scientists were not on the Indian Government rolls and had come here on private assignments. What the Indian side cannot figure out is where the hardline policies are being laid down when the talks seem to be going smoothly. One interpretation is that the sanction is having its own momentum. Within the administration, some State Department mandarins are pointing to the Pentagon and the DOD as the hardline sections, while they in turn say the State calls the shots.

If anything, Indian officials feel the Pentagon has considerably softened its attitude towards India. In fact, at the party to celebrate India's I-Day on Saturday, the maximum high-level representation came from the US defence services. The State Department was thinly represented, although Assistant Secretary of State Karl Inderfurth put in an appearance.