A shouting, shoving band of dissident worshipers disrupted religious services at the Washington Islamic Center yesterday morning, delaying the start of the first observances to be held there since the mosque was closed last March following a bitter three-year battle for control of the center.

Police in riot gear arrested 52 people inside the mosque after members of their group assaulted the center's director and turned the services into a shouting match. They were charged with unlawful entry and disrupting a religious service, police said.

The fracas delayed for two hours the 8 a.m. prayers observing Eid, one of the most holy days of the Muslim calendar, which celebrates the end of the month-long Ramadan fast. At least three Islamic ambassadors--from Sudan, Bangladesh and Saudi Arabia--were among about 1,000 people who came to the center on Massachusetts Avenue NW.

When dissidents attempted to disrupt the services a second time, police were asked by Sam Hamod, the center's director, to come inside the masjid or prayer room to prevent a recurrence of the disturbances. They remained inside lined up along the decorative tiled walls during the services.

Board chairman Omer Salih Eissa, the Sudanese ambassador, said yesterday the board intends to keep the center open and will rely on authorities to ensure the "safety of the worshipers and the sanctity of the mosque" if there are future disruptions.

"I think it is very clear to us that the Islamic community is determined to have a sense of unity and to have prayers in the center," Eissa said. "I think we'll rely on the authorities to maintain law and order according to the laws of this country."

The incident highlights the struggle that has raged between the center's board of governors, composed of the 29 Islamic ambassadors to the United States, and a faction led by Mohanned Asi, a 31-year-old American Muslim.

In dispute between the two groups is the method of choosing the center's imam, or religious leader. The board maintains that as the legal owner of the center since it was built in 1957, it has the right to appoint the imam.

But Asi and his followers, who include both Americans and foreigners, the bulk of whom appear to be Iranians, say that worshipers living in the Washington area and attending services at the mosque should be allowed to elect their own imam.

On a deeper level, however, the dispute revolves around differing visions of Islam in the modern world. Most of the center's ambassadorial board members subscribe to a philosophy that accommodates some of the secular aspects of Western thought and accepts some distinction between the political and religious realms. Asi's group of 100 to 200 people believe most of the center's ambassadors have fallen away from true Islam. Like the theocratic government of Iran, they adhere to a fundamentalist vision in which politics and religion are inseparable.

Asi served as imam at the center for nearly a year, even though his presence there was not authorized by the board. When negotiations between the two groups failed, the board, armed with a D.C. Superior Court decision that it was the rightful owner of the center, hired a private security service to physically eject Asi and his family last March. The board then closed the mosque for repairs, hoping that a cooling-off period would defuse the feud between it and the dissidents.

According to center director Hamod, yesterday's disturbance began as the service commenced. He said one of the dissidents grabbed the microphone and when asked to return it, "slammed me Hamod in the arm." Hamod said others began hitting and kicking him and when other individuals attempted to help him, a fist fight broke out.

Hamod left the prayer room to call the police and the worshipersfollowed him, leaving behind Asi and about 40 of his followers.

Police removed the dissidents, including Asi, one by one and cuffed their hands behind their backs. Worshipers waiting outside clapped and cheered. But as the dissidents were loaded into police vans, members of their group shouted support to their colleagues and yelled: "Police, get out of our mosque."

Among those arrested was Washington Times religion editor, William Willoughby, who was covering the event. Willoughby, who was released on a $525 bond posted by the paper, said that despite attempts to identify himself as a reporter to the police, he was arrested after a security guard claimed he was one of the demonstrators.

Later, when police were asked by Hamod to enter the prayer room to prevent more trouble, many of the worshipers were disturbed that they had not removed their shoes, an affront, in their eyes, to the sanctity of the newly refurbished room.

Yesterday's tumult dismayed many in the center's congregation, which is made up of Muslim professionals and business people and includes nationals from Islamic countries in Africa, the Middle and Far East, as well as Americans.

"I think it's a pity," said Ali Jafer, a student from the Sudan, "because this day should not be a day of violence but a day of reconciliation."

Also contributing to this story was Washington Post staff writer Alfred E. Lewis.