NEW DELHI, June 23.-The United States charge d'affaires in New Delhi, Gallen L. Stone, was called to the Foreign Ministry today for clarification of a report in The New York Times that two Pakistani ships had sailed from American ports carrying United States military equipment, including aircraft and spare parts for army vehicles.

However, neither the embassy nor the Indian Government had any details or confirmation of the report.

Foreign Minister Swaran Singh, who returned early today after a visit to six world capitals, said that the contents of the report were "contrary to assurances" that he had from American officials in Washington that military aid would not be provided to Pakistan.

Shown a copy of the report published in The Times, Mr. Singh said: "I cannot accept the correctness of the report. I got a clear assurance that no arms will be given to Pakistan."

Later, the spokesman for his ministry commented that the newspaper account contained "so much details and research work" that they could not dismiss its veracity. Indignant Members of Parliament demanded a detailed statement from Mr. Singh, which he promised to make tomorrow

Reports from Indian correspondents on Mr. Singh's visit to Moscow, Bonn, Paris, Ottawa, Washington and London, suggested that he had succeeded in impressing on world powers that they should discontinue military and economic aid to Pakistan to exert pressure on her to work out a political settlement in East Pakistan.

Twenty-five Members of Parliament marched to the United States Embassy today shouting anti-American slogans.