Rights groups say Zimbabwean police have intensified a clampdown on civil society organizations and democracy campaigners ahead of a referendum on a new constitution and crucial elections to end the nation's shaky coalition government.

Crisis in Zimbabwe, an alliance of rights groups, said Tuesday police raided the offices a member organization. The group said police on Monday seized files on political violence, funding details, DVD display materials, mobile phones and other equipment. Officials of the widely respected Zimbabwe Peace Project were accused of illegal importation of goods and `'possessing articles for criminal use."

No one was arrested. The officials deny any wrongdoing.

Last month, the head of the Zimbabwe Human Rights Association was granted bail after three weeks in jail on allegations of illegally obtaining voter registration documents.