UNTIED NATIONS, N. Y., Nov. 18—China accused India today of interfering in Pakistan's affairs and of obstructing efforts to restore peace on the subcontinent.

Fu Hao, a Chinese representative, in a statement that surprised diplomats by its toughness, charged in effect that subversive activities by India in East Pakistan had caused refugees to flee across the border.

The Chinese delegate did not mention India by name but spoke of a “certain country” in his statement in the General Assembly's Social Committee, which has been discussing humanitarian assistance to the Pakistani refugees.

His support of Pakistan's political position and his attack on India were unexpected to some delegates, who had felt that Peking's relations with India had been improving and that there was some doubt that China would give open backing to Pakistan in the deepening border conflict.

It was reported only yesterday that India planned to send a senior career diplomat to Peking as Ambassador on the understanding that the Chinese would reciprocate.

After the Chinese speech today, the reaction from Samar Sen, the Indian delegate, was that the Chinese representative had repeated the “standard line” taken in the past by Peking. Asked how China's harsh attack should be assessed in light of the planned ambassadorial exchange, he said, “Maybe the word hasn't filtered through yet.”

Mr. Fu, speaking last today after a score of delegates, insisted that Pakistan repeatedly had made proposals to relax tensions in the area and settle the problem of refugees but that these offers had been rejected by India.

He said of the Indians: “They continue to exploit the question of refugees from East Pakistan and to interfere in the internal affairs of Pakistan, to carry out subversive activities against her and obstruct the return of East Pakistani refugees to their homeland, making it impossible to reach a reasonable settlement on the question of refugees from East Pakistan.”

The Chinese delegate charged that India had used the same subversive tactics in trying to stir up a rebellion in Tibet. He said that when this was crushed by the Chinese people, “they coerced tens of thousands of Chinese inhabitants into going into their country, creating a so‐called ‘Tibetan refugee question.’

Mr. Fu told the committee that his Government regarded conditions in Pakistan as an internal affair to be settled by the Pakistani people and said that China “is firmly opposed to any country interfering in the internal affairs of other countries under the pretext of a so‐called refugee question or anything else.”

Earlier in the day, China defended her right to develop and test nuclear weapons on the ground that she did it in “self-defense and for a just cause.”

During a debate on disarmament, Saudi Arabia criticized China for her explosion of nuclear device yesterday. The explosion was reported by the Atomic Energy Commission in Washington.

In a reply to the criticism, two Chinese delegates spoke in succession in the General Assembly's Political and Security Committee. They said that such tests were justified by Peking's promise never to be first to use atomic weapons.

The remarks this morning by An Chih‐Yuan, the alternate delegate to the committee, and Chen Chu, the principal delegate, also served to set the stage for a full‐fledged Chinese policy declaration on disarmament, scheduled for Wednesday in the Assembly.

The Chinese delegates said they had no information from Peking on a nuclear text. But they told the committee that in general a distinction is necessary between “aggressors” and those developing such weapons for “self‐defense.”

Until China's speech attacking India this evening, Social Committee members with the exceptions of India and Pakistan had generally concentrated in their statements on the non political elements of aiding the refugees. Refugees began fleeing across the border after the Pakistan Army last March forcibly moved to quell a separatist movement in East Pakistan.

While many committee members called for a political settlement, they avoided blaming either party for the worsening conflict and were consulting on various moderate and neutrally worded texts that would call for a settlement without taking sides. China's statement today was expected to create a new situation and could stiffen Pakistan's bargaining position.