-LRB- CNN -RRB- -- U.S. President George Bush railed against the government of Zimbabwean president Robert Mugabe Monday , calling intimidation of opposition figures `` deplorable . '' Leading opposition figure Artur Mutambara was arrested following his criticism of President Robert Mugabe . `` The continued use of government-sponsored violence in Zimbabwe , including unwarranted arrests and intimidation of opposition figures , to prevent the Movement for Democratic Change from campaigning freely ahead of the June 27 presidential runoff election is deplorable , '' Bush said in a statement released by the U.S. Embassy in neighboring South Africa . Zimbabwean authorities Sunday arrested an opposition leader on charges stemming from his criticism of the government and its handling of the recent presidential election , an official with the opposition Movement for Democratic Change told CNN . Police in Harare surrounded the house of student activist-turned-opposition politician Arthur Mutambara and arrested him on charges of contempt of court and publishing falsehoods , MDC official Romualdo Mavedzenge said . While Zimbabwe authorities have arrested dozens of MDC supporters and activists over the past two months , Mavedzenge said `` this is the highest profile MDC official -LRB- arrested -RRB- since the March 29 election . '' Mutambara is president of an MDC faction that split from the main party headed by Morgan Tsvangirai . After Tsvangirai 's party won the majority of seats in parliament , the two leaders agreed to join forces in parliament under Mutambara 's leadership . Both charges stem from an opinion piece written by Mutambara in which he criticized President Robert Mugabe for the way the March 29 elections were handled . Raphael Khumalo , chief executive of The Sunday Standard , which published the article , was arrested last month on charges of publishing falsehoods . Bush said Mugabe 's government is failing on multiple levels . `` We call on the regime to immediately halt all attacks and to permit freedom of assembly , freedom of speech , and access to the media , '' Bush said . `` We urge the Southern African Development Community , the African Union , the United Nations , and other international organizations to blanket the country with election and human rights monitors immediately . '' Zimbabwe 's election commission said Tsvangirai won the March presidential election , but did n't win a majority of the vote , forcing this month 's vote . The MDC contested the results , saying Tsvangirai won outright , but decided to take part in the runoff and not cede the election to Mugabe .