Harare/Johannesburg - A senior US official called for the United Nations Security Council to take up the issue of growing violence in Zimbabwe as state media there reported Thursday the opposition (MDC) had begun attacking members of President Robert Mugabe's party.

Speaking in Pretoria, United States Assistant Secretary of State for Africa Jendayi Frazer said the US was increasingly concerned about violence and human rights abuses in Zimbabwe in the wake of disputed March 29 elections.

It was time for the UN Security Council to take up the issue, she urged.

Frazer also expressed support for MDC leader Morgan Tsvangirai's claim of victory over longtime leader Mugabe in the presidential election, saying the "most credible results" pointed to a clear victory for Tsvangirai and questioning whether conditions existed for a runoff.

The results of the elections have been withheld by the state- controlled election commission for nearly a month. Mugabe's Zanu-PF says neither Mugabe nor Tsvangirai won a clear victory and called for a runoff. The MDC has swung back to outright rejection of a runoff after saying it might take part if they could be sure it was free and fair.

Meanwhile, Zimbabwean state media began to carry reports of attacks by MDC supporters against Zanu-PF supporters in rural areas.

ZBC public television showed images of six houses belonging to Zanu-PF supporters it said MDC supporters had burnt down in Makoni North constituency.

Zimbabwean police spokesman Wayne Bvunzijena told Deutsche Presse- Agentur dpa five people had been arrested in connection with the attack.

The MDC immediately denied it was the work of its members, accusing the government of trying to deflect attention from the campaign of violence against MDC supporters by Zanu-PF youth militia and the military.

"The government thinks that it can make Zimbabweans and the world believe that? It just wants to heighten the level of violence against our supporters in which some have already lost their lives," said MDC spokesperson Nelson Chamisa.

The MDC claims 11 of its members have been killed as part of what it terms Mugabe's campaign to brutalize people into voting for him in a runoff, a claim the government and police have rubbished.

Deutsche Presse-Agentur dpa witnessed soldiers going from door to door last week in a suburb of Harare, an opposition stronghold, beating up men and boys.

Analysts have been touting a government of national unity as the most likely outcome to the political impasse but Zanu-PF and the MDC disagree on who would lead such a government.

The MDC says Tsvangirai should, while a state newspaper on Wednesday said Mugabe should.

Meanwhile a partial recount of both the presidential and parliamentary elections continued into a sixth day. With results from 2 out of 23 constituencies announced, the MDC and the Zanu-PF had both retained a seat. (dpa)