The United Nations says the Iraqi government is refusing to disclose civilian casualty figures for the past three months.

It a report issued Wednesday, the U.N. Assistance Mission in Iraq says this is the first time since it began issuing quarterly reports on the situation in Iraq that the Health Ministry has not released overall casualty figures.

The U.N. agency says the government of Prime Minister Nouri al-Maliki has accused it of exaggerating the civilian death toll in its last report, published in January. That report said more than 34,000 Iraqi civilians were killed and more than 36,000 wounded in 2006.

According to the U.N. agency, the number of civilian casualties rose in March after an initial drop in the second half of February after the U.S.-led coalition launched its new security plan for Baghdad.

The U.N. mission also expressed concern about the treatment of some 3,000 suspects detained in the new U.S. - Iraqi security crackdown. It said the Iraqi government has a poor record on handling detainees.

Some information for this report was provided by AFP, AP and Reuters.