HARARE , Zimbabwe ( CNN ) -- Zimbabwe 's President Robert Mugabe has warned that veterans he commanded in his country 's liberation war will take up arms again to prevent the opposition party from taking power . Zimbabwe 's President Robert Mugabe says war veterans do not want the opposition in power . Mugabe -- Zimbabwe 's only leader since that struggle ended in 1980 -- faces a June 27 runoff with Morgan Tsvangirai of the opposition Movement for Democratic Change ( MDC ) . Mugabe told supporters that Tsvangirai would turn the country back over to white control if he won the runoff . The veterans he led in a successful effort against a government dominated by the white minority were not prepared to recognize a Tsvangirai victory , Mugabe said . `` They said they got this country through the barrel of gun , so they can not let it go by a ballot , '' Mugabe said Thursday at a campaign rally in Murehwa . Tsvangirai was arrested twice Thursday . He was released Friday , but police impounded his two campaign buses . In the general election on March 29 , the opposition won a plurality in parliament . Weeks after the election , the Zimbabwe Electoral Commission announced that Tsvangirai won a plurality against Mugabe but that he failed to get the needed majority , making a runoff necessary . Human Rights Watch issued a report this week declaring the presidential election to be dead on arrival because of violence and intimidation by Mugabe 's followers -- including war veterans - against opposition supporters . Mugabe , at a rally in Chikomba District -- about 120 miles ( 200 km ) south of Harare -- seemed to support that conclusion . Learn more about Zimbabwe » . `` These areas , where the party lost on March 29 , need to be cleansed and I am confident this would be done on June 27 when we go to the polls . '' Mugabe said the MDC was a party `` for whites and not blacks . '' He also said the party was created and funded by the British . `` You saw the whites after the March elections running around thinking that they would repossess the farms , '' Mugabe said . `` They thought they had won . '' He said the opposition would not be allowed to `` give it back to whites . '' `` Guard your country jealously , '' Mugabe told supporters . Meanwhile , Zimbabwean authorities put more pressure on opposition figures Thursday , seizing a top leader and accusing him of treason . Police and the MDC confirmed Tendai Biti 's arrest and the charges he will face . Biti , secretary general of the MDC , was arrested when he arrived in Harare , Zimbabwe , from South Africa . Zimbabwe 's national police spokesperson Wayne Bvudzijena told CNN that Biti would be charged with treason and the communication of false information . The treason charge relates to a document published by the MDC before the March 29 vote which , the state alleges , contains subversive statements authored by Biti .
President Robert Mugabe says war veterans will fight to prevent change . Opposition party 's No . 2 facing treason charge after return to country . MDC leader Morgan Tsvangirai was detained twice Thursday .