The Bush administration is intervening with governments in southern Africa to prevent a Chinese ship carrying weapons for Zimbabwe's security forces from unloading its cargo, The Associated Press has learned. At the same time, the State Department's top Africa hand, Jendayi Frazer, plans to visit the region this week to underscore US concerns about the shipment. Frazer also will try to persuade Zimbabwe's neighbors to step up pressure on President Robert Mugabe's government to publish results from a disputed election that the opposition claims to have won, administration officials said Monday. US intelligence agencies are tracking the vessel, the An Yue Jiang, and American diplomats have been instructed to press authorities in at least four nations - South Africa, Mozambique, Namibia and Angola - not to allow it to dock, the officials told The Associated Press. The officials spoke on condition of anonymity in order to discuss delicate diplomatic talks. The ship, which is laden with large amounts of weapons and ammunition, already has been turned away from South Africa and Mozambique, and is now believed to be headed for Angola, possibly with a refueling stop in Namibia. The freighter left South Africa after a judge on Friday barred the arms from transiting South Africa and it was not immediately clear if US lobbying had influenced authorities in Mozambique who stopped it from docking over the weekend. Two officials said Washington's effort to block the ship from unloading its cargo was now concentrated on Namibia and Angola and that both countries were being told that allowing the An Yue Jiang to dock could harm their relations with the United States. There are fears that the arms, which include mortar grenades and bullets, could be used by Mugabe's regime to expand a clampdown on opposition supporters. The government has refused to publish the results of presidential elections held three weeks ago, and there are reports of increasing violence against the opposition. In Beijing, China's Ministry of Foreign Affairs had no immediate comment. South Africa's main trade union confederation has called on workers in other African countries to follow the example of South African dock and freight workers who said Friday they would not unload the ship or transport its cargo. The State Department endorsed that position on Monday. "Given Zimbabwe's current electoral crisis, we do share the concerns ... that these arms could be used against individuals who are merely trying to freely express their political will," said Kurtis Cooper, a department spokesman. "We call on the Zimbabwe government to immediately cease the perpetration of brutal acts against its citizens and strongly urge the regional leadership to enhance its intervention for an expeditious solution to the postelection crisis," Cooper said. The comments, prepared ahead of an expected announcement that Frazer will travel to southern Africa, come as the Bush administration has grown increasingly impatient with Mugabe - whose recent rule Secretary of State Condoleezza Rice last week called "an abomination" - and with Zimbabwe's neighbors for not taking a harder line against the octogenarian leader. The 14-nation Southern African Development Community, known as SADC, has been unwilling to take the tough stand on Zimbabwe as called for by western countries, notably Britain and the United States. Part of Frazer's planned trip is aimed at rallying support for action from SADC members, whose leaders met in a mid-April summit on Zimbabwe but could agree only on a weak declaration that failed to criticize the absent Mugabe, officials said.