A white college freshman from California is among three Americans being held under South Africa's state of emergency following his arrest Sunday at a mixed-race church service near Cape Town commemorating the 1976 Soweto riots, the State Department said yesterday.

Joseph Reed, a department spokesman, said Scott Daugherty of San Diego, identified by a family member as an 18-year-old student at Humboldt College in northern California, was being held in Polsmoor prison in Cape Town. U.S. diplomats have not been allowed to contact Daugherty, Reed said.

Reed identified the second American as Ronald S. Minor of Anaheim, Calif. He said that Minor was arrested Saturday in Cape Town but that he had no details. He said that U.S. consular officials have visited Minor and that a court date has been set.

Reed said he could not identify the third American because of privacy restrictions.

Under emergency regulations announced last Thursday by Pretoria, all meetings, including church services, called to commemorate the Soweto uprising were banned.

The Rev. Brian Burchfield, an American Lutheran pastor who was Daugherty's host in Cape Town, said in a telephone interview yesterday that the church service had been called in memory of Soweto and that police had confiscated church programs outlining the order of service.

Daugherty's sister, Jean Daugherty of Durham, N.C., said her brother, who studies journalism and political science, went to South Africa in April to spend the summer. She said he had been in frequent touch with the South African Council of Churches during his stay. The Johannesburg offices of the council were raided by security forces last Thursday.

Burchfield and his wife, Susan, also a Lutheran pastor, said Brian Burchfield drove Daugherty to the service on Sunday afternoon at St. Nicholas Anglican Church in Elsie's River, a mixed-race township near Cape Town. Brian Burchfield said he returned to pick up Daugherty 45 minutes later.

"People came up to me and said, 'Father, you must help. The police are here,' " Burchfield said.

Burchfield said all 250 worshippers at the service were detained by police. Police also detained Burchfield after he inquired about Daugherty, he said. He said he, Daugherty and a third man were the only whites among the detainees.

In the courtyard of police headquarters in nearby Bellville, Burchfield said, male and female churchgoers were separated. He said those 14 years old or younger eventually were released. A frightened black girl of about 5 or 6 refused a police offer to drive her home and went to prison with black friends, he said. "She wouldn't let police touch her," he added.

Burchfield also was released after police checked his identity with a U.S. consular official, Burchfield said.

"What happened to Scott happens to thousands of people here all the time," said Burchfield, who was assigned to South Africa with his wife in January. "If people can understand Scott, they can also understand the daily terror this government imposes through their repressive means."

Daugherty's sister said apartheid was an issue her brother had felt strongly about since he heard Anglican Bishop Desmond Tutu speak two years ago in Atlanta.