The prime minister's office on Saturday released comments Prime Minister Nouri al-Maliki made to the state-run Iraqiya TV channel during which he defended the detentions.
He said officials had reason to believe the people arrested were a threat to security but he gave no further details. He did not say when the sweep took place.
The Baath Party ruled Iraq under Saddam Hussein but now is outlawed under Iraqi law, and the prime minister has often accused ex-Baathists of planning terrorist attacks across the country.
Many Sunnis, who were disproportionately represented in the party leadership, feel the attacks against Baathists are a thinly veiled way to go after Sunnis.