Zimbabwe's government says it is investigating the origins of a surprise statement issued by the country's independence war veterans attacking President Robert Mugabe as dictatorial.

In its first public response to the statement issued Thursday by Mugabe's traditionally loyal supporters, the ministry of war veterans said the authors should be held accountable.

The government statement released Friday urges all war veterans to remain loyal to the 92-year-old Mugabe, who has been in power since the country won independence from white rule in 1980.

Representatives of the war veterans were not immediately available for comment Saturday.

Their strongly worded statement, in which they said they will not campaign for Mugabe again, was their first significant break with the president, whom they have been quick to defend even with violence.