HARARE, Zimbabwe (AP) — Zimbabwean police on Thursday arrested two more members of Prime Minister Morgan Tsvangirai’s office staff, said his party, raising the number detained to six in what President Robert Mugabe’s political rivals have described as a campaign of intimidation ahead of elections.

Tsvangirai takes the attacks on his staff as “an affront to democracy and the rule of law,” said his party, the Movement for Democratic Change, in a statement.