JOHANNESBURG, SOUTH AFRICA — The U.S. joined calls Thursday for an arms embargo against Zimbabwe as the Chinese weapons shipment that sparked a scandal turned for home, shunned by ports in southern Africa.
Young militiamen known as "green bombers" and war veterans have been attacking opposition activists and supporters in rural areas of Zimbabwe, according to human rights organizations and the opposition party Movement for Democratic Change.
Britain has urged an international arms embargo against Zimbabwe because of the violence, and South African Nobel laureate Desmond Tutu and the top U.S. diplomat on Africa, Jendayi E. Frazer, joined the call Thursday.
China's Foreign Affairs Ministry confirmed that the ship carrying ammunition and weapons was returning home after failing to unload its cargo.
The government of Zimbabwe President Robert Mugabe appears increasingly isolated. Most of the country's neighbors in southern Africa object to transshipment of the arms in their territory. The government of South Africa was willing to let them pass through, but transport was thwarted by a court challenge and a blockade by trade unions.
The results of Zimbabwe's presidential election remain secret nearly a month after the vote. According to an independent projection based on 5% of the vote, opposition candidate Morgan Tsvangirai of the Movement for Democratic Change won more votes than Mugabe, but not enough to avoid a runoff.
The ruling ZANU-PF party appears increasingly divided over efforts to cling to power.
Human rights activists and doctors estimate the number of assaults against opposition party supporters or activists at 330 to 490 and say that 10 people have been killed. They have not provided details.
Some ruling party figures believe the violence against opposition activists in rural areas will not keep Mugabe in office and will only harden public sentiment against him, but others are convinced it is the only choice.
"We need to ensure that ZANU-PF wins, by any means necessary," said one provincial ruling party official, who spoke on condition of anonymity. He said the violence by militias would show rural voters that the MDC has no chance of taking power if a runoff election is held, as expected.
Another strategy would be to reduce the number of polling stations in the opposition's urban strongholds, he said.
At a news conference Thursday in Pretoria, South Africa, Frazer said it was clear that Mugabe had lost the election. A recount of votes for 23 parliamentary seats currently underway and long-delayed presidential results had no credibility, she said.
Frazer, U.S. assistant secretary of State for Africa, called for a United Nations Security Council debate and imposition of an arms embargo.
"I think the debate itself would send a great warning to others who would think about sending arms into Zimbabwe today, including the Chinese, so there is value in even having the debate," said Frazer, who is in the region for talks on the situation with regional leaders and Tsvangirai.
Tutu called on regional leaders to press Mugabe to leave office graciously and called for an embargo on arms until Zimbabwe's political crisis is resolved.
Independent economists estimate Zimbabwe's inflation rate at more than 200,000%. The country is plagued by severe food shortages and a lack of foreign currency to purchase the staple food, maize.
Analysts say that even if Mugabe survives the crisis, the economy might force him out.
"The sheer audacity of having an election, losing it and not even announcing it -- that kind of thing is the end of a regime. It can be dragged out and it can be violent, and it can be tragic," said economist Jeffrey Sachs, director of Columbia University's Earth Institute. "I don't believe an 84-year-old despot who lost an election can hang on for very long."
Underscoring the Mugabe regime's sensitivity over the Chinese arms shipment, the state-owned Herald newspaper denied Thursday that the weapons would be used against civilians. It said China's share of the world weapons trade was minuscule compared with that of the United States.