PRETORIA, South Africa — A top official in the party of Zimbabwe's prime minister, Morgan Tsvangirai, says he is concerned that political violence is again taking root ahead of a March 16 referendum on a new constitution and elections later in the year.

Finance Minister Tendai Biti said in South Africa on Saturday that he is also worried that some foreign observers will not be allowed into Zimbabwe to monitor the voting. Top Zimbabwean officials have said that African and regional monitors will be allowed, but Western observers will be banned.

Tsvangirai's party, formerly the opposition, is in a shaky coalition with President Robert Mugabe's party.

Biti has previously complained of arson and numerous other attacks this year that he has blamed on Mugabe's supporters. Both Mugabe and Tsvangirai have called for violence-free elections.