"The Secretary-General strongly condemns this criminal act and hopes that it will not deter the Constitutional Commission from completing its important task on time," Mr. Annan said in a statement issued by his spokesperson on the assassination of Mijbil Sheikh al-Issa, who was gunned down together with an adviser to the commission, Dahmen al-Jabour.

"The Secretary-General notes that Mr. Issa was one of the 15 Sunni representatives who had recently joined the Commission with the purpose of drafting a new constitution through an inclusive process that is responsive to the needs of all Iraqi constituencies," the statement added.

Barely a month ago, Mr. Annan welcomed the Iraqi agreement to expand the Constitution Drafting Committee by adding Sunni Arabs, a long-term UN goal since the 30 January elections for the Transitional National Assembly when Sunni Arabs largely stayed away, hurting efforts to attain the inclusion of all segments of society.

Sunni Arabs, the dominant political force in Saddam Hussein's ousted regime, represent about 20 per cent of the population. Shiite Arabs, about 60 per cent of the electorate, voted enthusiastically and dominate the assembly together with the mainly Sunni Kurds, who also turned out en masse and represent about 20 per cent.

Mr. Annan's Special Representative for Iraq, Ashraf Qazi, also condemned today's assassinations as well as the recent wave of killings and suicide attacks across the country.

"These are unacceptable acts of violence under any circumstances. These heinous acts are against the principles of Islam and the human values of all religions and beliefs, and must be condemned," Mr. Qazi said in a statement.