Johannesburg - Zimbabweans were looking Friday to a meeting of President Robert Mugabe's Zanu-PF party for a sign of whether the 84-year-old leader intended to square off against opposition leader Morgan Tsvangirai in a mooted second round of voting for president.

The politburo (highest-decision making body) of Mugabe's Zanu-PF was due to meet later Friday to discuss its options following last weekend's combined presidential, parliamentary and local elections.

The party was soundly defeated by Tsvangirai's Movement for Democratic Change in elections to the 210-seat House of Assembly (lower house of parliament) by 97 seats to the MDC's 109.

Six days after voting the official results of the presidential vote have yet to be announced but a second round pitting Mugabe against Tsvangirai has emerged as a strong possibility.

The MDC has declared a runoff unnecessary claiming Tsvangirai the outright winner based on its own, unofficial vote count but a spokesman for Mugabe's party said neither candidate won outright and vowed Mugabe would "fight to the last" in a second round.

Zimbabwe's election standoff was expected to dominate talks in London between South African President Thabo Mbeki, who has led previous attempts to defuse political tensions in Zimbabwe, and British Prime Minister Gordon Brown.

Mbeki and Brown were scheduled to meet Friday ahead of Saturday's Progressive Governance summit of centre-left leaders, South African radio reported.

As tensions caused by the long wait for the election results edged higher the MDC accused Mugabe of preparing a crackdown on the opposition during a mooted second round of campaigning.

"They are preparing for a war," MDC secretary general Tendai Biti said in an interview with South African radio, urging the international community, including Mbeki, to be on the watch for a violent turn of events.

On Thursday, in a first sign of a security clampdown, police arrested two foreign journalists, including award-winning New York Times journalist Barry Bearak, and ransacked a hotel room used by the MDC to "look for documents."

Police accused Bearak of violating journalism laws, a U.S. consular official was quoted by the New York Times as saying.

An American employee with the U.S. National Democratic Institute (NDI) was also arrested, his employers confirmed. The charges against him were unclear.

The MDC also alleged Friday that Mugabe was preparing to change the law to allow a runoff within 90 days, instead of 21 days as currently called for by law, and rule by decree in the interim.

"He would be ruling illegally because his term expired on March 28 (the day before elections)," Biti charged.

Zimbabweans had been hoping to know the outcome of the presidential results by Friday after the Zimbabwe Electoral Commission said it would issue results within six days of voting, but that looked increasingly unlikely.

ZEC instead was issuing results from the 60-seat Senate election at the same snail's pace as the parliamentary vote.

With 10 seats announced Mugabe's Zanu-PF party and the MDC were neck and neck with 5 seats each. (dpa)