British prime minister Gordon Brown said today he is appalled by signs Zimbabwe's government was resorting to violence in an election standoff and warned president Robert Mugabe the world was losing patience.
Human rights organisations and the opposition Movement for Democratic Change (MDC) say Mugabe has unleashed a campaign of violence after the ruling ZANU-PF party lost control of parliament in a March 29th election.
Official results of a presidential vote - which the MDC says its leader Morgan Tsvangirai won - have not been announced.
"I cannot understand why it is taking so long to announce the result of the presidential elections," Mr Brown said in a statement, his toughest so far on the Zimbabwe situation.
"I am appalled by the signs that the regime is once again resorting to intimidation and violence," he said.
"We will be vigilant. The international community will remain careful to do nothing to undermine efforts to secure an outcome that reflects the democratic will of the people of Zimbabwe," he said.
"But the international community's patience with the regime is wearing thin," Mr Brown added.
Britain, the former colonial power, has often clashed with Mugabe, who has ruled Zimbabwe since independence 28 years ago.
Since the election, the British government has measured its words carefully for fear Mugabe could portray its comments as British interference in the country's politics, analysts say.