(Adds torture allegations, justice minister)

By Cris Chinaka

HARARE, April 25 (Reuters) - Armed riot police raided the headquarters of Zimbabwe's main opposition party on Friday and detained scores of people in the biggest crackdown on the MDC since disputed elections last month, officials said.

Angola said a Chinese ship with arms bound for Zimbabwe would be allowed to offload some cargo, but not the weapons.

Zimbabwe's Movement for Democratic Change (MDC) says its leader Morgan Tsvangirai beat President Robert Mugabe in the March 29 election, and results showed it had also ended the ruling party's 28-year hold on parliament.

A delay to the presidential result and a recount of some parliamentary votes has brought growing international pressure on Mugabe, 84, and stoked fears of bloodshed in a country already suffering an economic collapse.

The refusal earlier this month of regional states to allow the Chinese ship to unload the arms marked what appeared to be a shift in policy after years of a soft approach to Mugabe, by South African President Thabo Mbeki in particular.

Angola's state-run news agency ANGOP said Angola had authorised the ship to offload goods but not the military materials. China said the ship would head home.

South Africa's U.N. envoy said the U.N. Security Council would hold its first session on the post-electoral crisis in Zimbabwe next week and South Africa would not oppose it.

Ambassador Dumisani Kumalo of South Africa said someone from the U.N. secretariat would brief the 15-nation council, probably on Tuesday, on developments in Zimbabwe.

A Western diplomat on the council said Britain had requested the meeting and that the council was unlikely to take any action in the form of a statement or resolution.

But the diplomat said the meeting would be useful in ratcheting up pressure on Zimbabwean President Robert Mugabe to release the results of the March 29 vote.

TORTURE ALLEGATIONS

Mugabe remains defiant as Zimbabweans anxiously await results from an election they hoped would bring relief from severe shortages of basic goods and a staggering inflation rate of 165,000 percent -- the world's highest.

Dozens of riot police detained around 100 MDC supporters who were taken away in a crowded police bus, a Reuters witness said. The MDC said 200 to 250 police took part in the raid and they also took away computers used by the election command centre.

An MDC statement said armed police took away hundreds of people who had sought sanctuary at the party's headquarters after fleeing various parts of Zimbabwe, "where the regime has been unleashing brutal violence".

Spokesman Nelson Chamisa said: "They are trying to destroy evidence of their brutality."

Police said the raid targeted people who had sought refuge with the opposition after committing crimes outside Harare.

"Some of them are not office workers at all. We are busy screening them. There are some cases we are investigating and we will release those who have not committed any crime," said police spokesman Wayne Bvudzijena.

South Africa's eTV showed footage of heavily bandaged Zimbabweans in a hospital who said they were tortured because they were suspected of being MDC members. One of them had what he said were burn marks over much of his back.

Mugabe, a hero of the independence struggle, accuses the opposition of conspiring with Western critics to oust him down.

Opening Zimbabwe's international trade fair in Bulawayo on Friday, Mugabe renewed his attacks on former colonial power Britain and other Western nations for leading what he called a shameless campaign against his government.

Zimbabwe's state-run Herald newspaper called African leaders "myopic stooges" for joining the Western criticism of Zimbabwe's handling of the election.

The top U.S. diplomat for Africa, Assistant Secretary of State Jendayi Frazer, met Tsvangirai in South Africa and "they agreed that, given the long delay, any results will have limited credibility at this point," a U.S. Embassy statement said.

"We assured the MDC that we would look at additional international action to address, and bring attention to, the evolving human rights and humanitarian crisis in Zimbabwe," Frazer said in the statement.

Zimbabwe's justice minister hit back.

"Frazer's comments expose Tsvangirai and his MDC for what they really are: an Anglo-Saxon project designed to defeat the gains of the liberation struggle," Patrick Chinamasa said in a statement on ZTV. (Additional reporting by MacDonald Dzirutwe in Harare and Louis Charbonneau at the United Nations; writing by Michael Georgy; editing by Philippa Fletcher)

AlertNet news is provided by