By Nelson Banya
HARARE (Reuters) - Zimbabwean President Robert Mugabethreatened on Monday to arrest opposition leaders over electioncampaign violence for which his opponents blame ruling partysupporters.
Prime Minister Gordon Brown, branding Zimbabwe's governmenta "criminal regime", joined U.S. President George W. Bush inurging Mugabe to allow international monitors to ensure a freeand fair presidential run-off election on June 27.
Opposition leader Morgan Tsvangirai has been repeatedlydetained during his campaign, but has faced no charges. HisMovement for Democratic Change says 66 people have been killedin the election violence by ruling ZANU-PF supporters.
Mugabe blames the opposition for the disturbances.
"There is now a pattern readable across the country andthat has now to stop," he told a campaign rally in Kadoma, 150km (90 miles) south of the capital Harare.
"We are warning them that we will not hesitate to arrestthem, and we will do that in broad daylight. They think theyare protected by the British and the Americans. The law of thecountry has to be observed."
Mugabe is battling to keep his 28-year hold on power in acountry suffering economic collapse. Tsvangirai won the firstpoll in March but without enough votes for an outright victory,official results showed.
Brown, at a joint news conference with Bush in London, saidZimbabwe's government was an "increasingly desperate andcriminal regime" and accused it of orchestrating the violence.
"Mugabe must not be allowed to steal the election," hesaid.
"We call for Zimbabwe to accept a United Nations humanrights envoy to visit Zimbabwe now and to accept internationalmonitors from all parts of the world who are available toensure that this is a free and fair election," Brown said.
HARSH WORDS
Former colonial power Britain has long been critical ofMugabe but has increased the harshness of its language inrecent days.
A senior U.N. envoy, Assistant Secretary-General forPolitical Affairs Haile Menkerios, arrived in Zimbabwe late onMonday for a five-day visit to assess Zimbabwe's political andhumanitarian crisis before the run-off vote.
"I'm here to make an assessment of the whole situation andreport back," he told journalists, adding that he would meetMugabe during his visit.
The last senior U.N. official to visit Zimbabwe was U.N.habitat head Anna Tibaijuka, who produced a damning report onthe government's shantytown clearance exercise in 2005.
Observers from Western countries were barred from the firstround ballot on March 29 and are not being allowed in for therun-off. The African Union and the Southern African DevelopmentCommunity will send teams.
Bush supported Brown's call.
"We will work with you to ensure these good folks have freeand fair elections to the best extent possible, which obviouslyMr Mugabe does not want to have," he said.
Mugabe, 84, has held power since independence from Britainin 1980. His ZANU-PF lost control of parliament in the March 29election, but the president has the greatest say in running thecountry.
Critics say the economy has been ruined by Mugabe'spolicies, such as seizing white-owned farms to give to landlessblacks. He says Western sanctions are responsible.
Zimbabwe's once prosperous economy has collapsed, withofficial inflation running at 165,000 percent, unemployment ataround 80 percent and food and fuel in short supply. Millionsof Zimbabweans have sought work abroad, most heading to SouthAfrica, where their presence has stoked social tensions.
Zimbabwe ordered international aid agencies to stop work onJune 4, accusing them of working against ZANU-PF.
(Additional reporting by Mike Saburi and Katherine Baldwinin London, editing by Tim Pearce)
