Rasulan Bibi, a craggy-faced 70-year-old beggar whose husband and son were killed during Bangladesh's bloody liberation war in 1971, squatted in her 4-by-5-foot dirt-floored bamboo hut, boiling rice and shooing flies off her three grandchildren while she reflected on the cruel twists of history that have left her and 250,000 other war victims stranded in squalid detention camps with neither citizenship nor hope.

Wailing above the din of crying and coughing children, Bibi said she and her husband migrated here from Calcutta when India won independence and the Subcontinent was partitioned to create West and East Pakistan.

"We fought in 1947 so there would be a Pakistan. We fought in 1971 to save Pakistan. Now, Pakistan says it doesn't want us, and we have nowhere to go. Our lives are ruined," said Bibi, before setting off to beg her usual 5 taka (20 cents) a day in the teeming streets of the capital.

Bibi and the 20,000 other detainees crowded into the Mohammedpur camp on the outskirts of Dhaka are among the quarter million refugees who are collectively called, imprecisely, "Biharis" because many of them fled the Indian state of Bihar following waves of Moslem-Hindu communal riots in the aftermath of independence from Britain.

They refer to themselves as "stranded Pakistanis," because they were put into 66 detention camps after siding with Pakistan in the 1971 civil war that resulted in the creation of Bangladesh out of East Pakistan.

"We can't even call ourselves refugees, because a refugee is someone who flees from his country. In our case, the country fled from us," said Nasim Khan, a Bihari community leader who for 11 years has fought for repatriation to Pakistan.

The Mohammedpur camp, a labyrinth of sagging, tin-roofed bamboo shacks in which families of 10 often are squeezed into 20 square feet, is practically in the shadow of the unfinished but futuristic parliament building designed by the American architect Louis Kahn.

The camp has known despair before, its inmates say, but not so much as now because a brief glimmer of hope for mass repatriation appears to have been dashed.

After a year of no official repatriations, 4,600 Biharis were evacuated to Pakistan during the last two months of 1982 in a $1.5 million airlift that was financed by Saudi Arabia, Kuwait and other Persian Gulf states and assisted by the United Nations High Commissioner for Refugees (UNHCR).

In the Mohammedpur camp and others like it throughout Bangladesh, expectations soared as detainees spoke excitedly about a return to the conditions of the mid-1970s, when, under an agreement among India, Pakistan and Bangladesh, more than 121,000 Biharis were moved to Pakistan over five years.

But because of a shortage of funds--and a reluctance by Pakistan to accept any more Biharis--the airlift was stopped, and thousands of detainees who had submitted repatriation appeals based on hardship have been left stranded again. The last group left here Dec. 11 on a Saudia airliner, and Bihari leaders said there are no plans for further evacuations.

For those Biharis lucky enough to be able to afford it, there is a way out. Each year, hundreds of them move out from Saidpur, in northern Bangladesh, and after paying the equivalent of $120 to Indian and Bangladeshi contacts on the border, travel by train across India and illegally enter Pakistan.

Relief workers said that Saidpur, which after the 1971 civil war was 90 percent Bihari, is now down to 50 percent to 60 percent Bihari, partly because of the illegal emigration to Pakistan.

Nasim Khan, who was born 59 years ago in Patna, Bihar, and served as a guard for the East Indian Railroad until India was partitioned and he moved to what used to be East Bengal, said that in all of 1982, only 5,694 Biharis were repatriated. Even if that modest rate was maintained, he noted, it would take a generation to evacuate the current detainees, and population growth would erode any progress in the long run.

"We are kept in these concentration camps because we stood for a united Pakistan and stood by the Pakistani Army. We are an irritating reminder of those days, and for that we are condemned to suffer," said Khan, who in March 1979 led nearly 50,000 Biharis on an attempted march through India to Pakistan. They were stopped at the border by Bangladeshi authorities, and Khan was arrested.

In another desperate bid for repatriation, he called for mass self-immolation by Biharis two years ago, but called off the protest after receiving assurances of action by both the Pakistani and Bangladeshi governments.

Mohammed Shukruddin, a former jute baler from Bihar who moved to East Pakistan in 1947 and lost his house in Narangang in the 1971 war, said that as general-secretary of the ihari community at Mohammedpur he has been fighting an uphill battle to keep the camp together.

But, he said, the International Committee of the Red Cross, which until a year ago provided 6 1/2 pounds of wheat per inmate each month, has cut back its relief program, and the Bangladesh government has also scaled back its assistance. The detention center was originally named "Geneva camp" by the Red Cross organization.

The Saudi-based Moslem League recently paved a few narrow streets in Mohammedpur with brick and built some latrines, but those improvements seem overwhelmed by the general decay of the 11-year-old camp.

Hundreds of impoverished Biharis--many of them rickshaw pullers who earn 20 taka (80 cents) a day when they can find work--are crowded into crumbling warehouses in which tattered burlap bags and blankets are used as room dividers. Some of the tin-roofed shelters are so hot and crowded in the summertime that their occupants flee and sleep in footpaths or in mosques in Dhaka. Roof supports in some of the shanties have collapsed, and families crawl about on the dirt floor with a three-foot overhead.

"This is not a refugee camp. It is a concentration camp. It is worse than Hitler's camps, because there you were put in a gas chamber, and it was over. Here, there is only lingering death," Khan said.

Many of the Biharis are tubercular, according to relief workers here, and the medical services are scant because of a lack of funding. The Mennonite Central Committee, which operates sanitation and other self-help programs at other camps, does not have a program at Mohammedpur because, one relief worker for the committee said, it is considered "better off" than some camps.

Bangladesh government officials, who call the Biharis "nonlocals," say they would like to see all of the camp inmates either go to Pakistan or become assimilated here. "We are willing to absorb them outside the camps, but they want to go back. When they express their allegiance to Pakistan, what can we do?" one Foreign Ministry official asked.

Pakistani President Mohammed Zia ul-Haq, who has described Pakistan as a "homeland for all Moslems," has complained that his country is already strained by 2.8 million Afghan refugees and cannot afford an additional influx of Biharis.

But the Biharis maintain that once repatriated to Pakistan, they could join the migrant work force in the Persian Gulf and generate considerable foreign exchange for Pakistan. They complain that they have received little backing from the more highly educated and financially better-off Biharis who have already moved to Pakistan, and that the world community, for the most part, has ignored their plight.

An exception, Nasim Khan said, is Australia, where Prime Minister Malcolm Fraser has asked that 10,000 visas be issued to Biharis to settle there.

The Biharis say, and voluntary agency relief workers confirm, that the Biharis are often ostracized by the Bengali community here, with virtually no intermarriage and very little social contact. "Unless Pakistan opens its doors, there just isn't much future for them here," a Bangladeshi working for an international relief agency said.

Sitting in a ramshackle office in Mohammedpur topped with a Pakistani flag, Khan concurred.

"There was a bitter war between Bangladesh and Pakistan, and thousands were killed. Now there are good relations, trade and all kinds of agreements. Why has this human problem not been solved? The cry of the world is heard for the Afghans. Why can't the same cry be heard for us?" Khan asked.