Zimbabwe's most prominent opposition leader, his face swollen and a large gash on his head, was taken to a hospital Tuesday under police guard after appearing briefly in court along with about 50 activists arrested while trying to attend a prayer meeting.

A crowd outside the court sang and waved the opposition party's open hand salute as Morgan Tsvangirai and about six other injured activists left court. Tsvangirai walked slowly and was able to board an emergency vehicle unaided, but appeared disoriented. He was not among those who returned the salute.

As the activists, some bruised and bandaged, shuffled into court Tuesday, many sang and chanted in defiance of a heavy police presence. Tsvangirai, the leader of the Movement for Democratic Change, stood in the courtroom but did not chant or sing. He had a large gash on his head with about 10 stitches, and his face and eyes were badly swollen.

Their lawyer, Beatrice Mtetwa, said no charges were immediately filed and the state prosecutor had no instructions. She said legal representatives were seeking to clarify with the attorney general whether the activists would be released. The court adjourned for lunch then several of the activists — including Tsvangirai — were taken to the hospital.

The U.S. ambassador to Zimbabwe told the British Broadcasting Corp. that a local civil rights activist was permitted to see Tsvangirai Tuesday and reported that he was in "very grave condition."

"He is apparently suffering from some kind of head injuries that have left him disoriented and not clearly focused mentally," Ambassador Christopher Dell said.

Colleagues said Tsvangirai was tortured after being arrested when police crushed the gathering on Sunday that was organized as a prayer meeting by a coalition of opposition, church and civic groups under the "Save Zimbabwe" banner.

Many members of the group brought from jails to the magistrate's court Tuesday in the open bed of a large police truck arrived singing and chanting, but Tsvangirai was silent. Police presence was heavy.

Late Monday, High Court Judge Chinemberi Bhunu had ordered police to allow Tsvangirai and others to receive immediate medical treatment and access to their lawyers.

Bhunu said that if police refused to comply, he wanted to see the prisoners in his court by Tuesday morning. He also ordered they be charged or released by noon Tuesday. Instead, they were brought to the magistrate's court hours after Bhunu's deadline.

Doctors for Human Rights said in statement that at least 20 people were in urgent need of medical attention, including Tsvangirai, after Sunday's unrest.

One activist, Lovemore Madhuku, arrived at the court Tuesday with a bandaged arm. Another, Greg Kwinje, had head wounds around his ear. "Save Zimbabwe" members outside the court said they were worried that their friends might have internal injuries because of police beatings.

One opposition activist, Gift Tandare, was shot dead in unrest Sunday surrounding the prayer meeting. Two mourners were slightly injured Tuesday at his funeral in skirmishes with police.

As the clampdown continued, police raided the main office of the Zimbabwe Congress of Trade Unions.

"Staff were harassed, threatened, some were slapped and beaten up. All offices were searched and flyers, files and some video tapes were seized," the union said in a statement. It said the financial administrator, Galileo Chirebvu, was taken away by police who had a search warrant and said they were looking for "subversive material."

United Nations High Commissioner for Human Rights Louise Arbour added her voice to mounting international criticism of Zimbabwean authorities.

"This form of repression and intimidation of a peaceful assembly is unacceptable, and the loss of life makes this even more disturbing," she said. U.N. Secretary General Ban Ki-moon, the U.S. State Department, the European Union, Amnesty International and the human rights committee of the International Bar Association also have expressed concern and condemnation.

Opponents of President Robert Mugabe blame him for acute food shortages, inflation of some 1,600 percent — the highest in the world — and repression and corruption. They have demanded the ouster of 83-year-old Mugabe, Zimbabwe's only ruler since independence from Britain in 1980.

Zimbabwe's Information Minister Sikhanyiso Ndlovu said in a radion interview Tuesday that the police had been attacked by opposition activists.

"The opposition has been involved in violence, caught by police with weapons of destruction and destroying cars and stores and beating up people," Ndlovu said. "They've been beating up police you know. That is what government cannot tolerate."