KARACHI, PAKISTAN.- Pakistan Government sources reported today that China had ordered an interest-free loan of $20-million not tied to the purchase of Chinese products.

The Islamabad Government said this was the first such loan it had been offered by China. Government sources and newspaper editorials drew critical comparisons between the reported Chinese offer and United States aid, which has been suspended since March 25, when the Pakistan Army moved against Bengalis of East Pakistan who were seeking autonomy.

"If the United States tells us to go to hell." an official said privately, "we have no alternative but to turn to China." Yesterday, Pakistan served notice on all governments that aid for East Pakistan would be gratefully accepted but only for distribution by the Pakistan Government. This is a sticking point with a number of relief organizations that wish to be certain aid is used as intended by donors.

FOREIGNERS ARE BARRED

In cyclone-devastated and wartorn East Pakistan, the military government has declined to permit aid distribution by foreigners. "The outside world win simply have to take our word for it that aid will be effectively distributed by us," Lieut. Gen. Tikka Khan, governor of the province, said several days ago.

Objections have been raised by some organizations to the expropriation by the Pakistan troops there of vehicles, boats and other donations from the United States, Japan and other nations.

Pakistan has been the recipient of over $4 billion in aid from the United States since 1957. China signed its first aid agreement with Pakistan in 1955, and since then has offered about $113-million in loans.

Newspapers here, which are closely censored by the Government, commented sourly on the announcement by Senator Edward M. Kennedy yesterday that the United States would provide $2.6-million in aid to Pakistani refugees in India.

Newspaper accounts here carried such headlines as "Dollars to Feed Miscreants" and "U.S. Aid for East Pakistan is in India." More than a million Bengalis have crossed Into neighboring India. Observers describe them as refugees fleeing for their lives.

INFILTRATORS, PAKISTAN SAYS

Pakistan charges that most of them are Indian infiltrators who were forced to flee by the Pakistan Army.

United States aid to Pakistan is believed to be crucial for the maintenance of Pakistani currency.

Some Americans here argue that aid should be stopped completely on the grounds that it would never reach the people for whom it is intended.

In fact, aid to East Pakistan must arrive by sea and East Pakistan's only important deep- water port, Chittagong, remains separated from most of the country because its rail link to the north has been cut by a demolished bridge.

These Americans feel that an occupation army of West Pakistani Punjabis could not be relied upon to take care of East Pakistan hostile population of Bengalis.

Other Americans argue, however, that only through aid can "channels to Pakistan be kept open."