On a street off Al-Gah Square, near the abandoned Jewish quarter, is a small restaurant called the Restaurant of Light. The owner, Ahmad Youssef, alias Amath, sits cross-legged on a bed in the back room as his Vietnamese wife, sepah, cuts vegetables for the evening dinner customers.

Outside in the restaurant, Muhammad Abdullah Nagi, co-owner of the restaurant , watches his Chinese wife fry oil for potatoes, and his almond-eyed children at play. Like members of most of the 50 Vietnamese refugee families in North Yemen , Mr. Nagi's father was a Yemeni migrant worker in Vietnam. His mother is Vietnamese. In 1976, one year after the Communist takeover of South Vietnam, an agreement was reached under which two planeloads of Yemeni-Vietnamese were evacuated to North Yemen.

These refugees spread to the towns of Sanaa, Ibb, Taizz, and Hodeida, most of them opening up restaurants serving Vietnamese and Yemeni cuisine.

"The Vietnamese government told us we were foreigners, and to get out," Mr. Nagi says in fluent Arabic. "We didn't like the Communists, so we left."

Ahmad Youssef, though a full-blooded Vietnamese, came with the wave of refugees to North Yemen because of what he said was the Communist government's persecution of Vietnam's Muslim minority.

"The Communitst government would prevent Friday prayers in the mosque by calling community meetings. Muslim schools were forbidden."

There reportedly are about 30,000 Muslims in southern Vietnam, the descendants of migrants over the past 200 years from Malaysia, Singapore, and Indonesia.

In Chau Giang Chau Doc Province, where he used to live, Mr. Youssef served as the secretary to the Islamic mufti at one of the country's 20 mosques. Like a good Muslim, he has made the hajj (pilgrimage) to Saudi Arabia.

Although the Yemeni-Vietnamese are reluctant to talk about it, they have had a hard time acclimating themselves to rugged, tribal Yemeni society, where kinship ties in the mountain villages still play an important part in who and what you are.

The Vietnamese women in their black trousers and tied-back hair are a sharp contrast to the heavily veiled Yemeni women. As a result, the Vietnamese keep to themselves.

"We're not 100 percent Yemeni," says one of them unhappily, "so we're not as good."

The North Yemen government has done little to help the Vietnamese settle into their new surroundings. Moreover, because of the problems the new immigrants have had in adjusting, the government now limits the number of Vietnamese entering the country.