The US has put a $10m bounty on his head. The party, which has been an underground movement since the 2003 invasion of Iraq, has vowed to continue its armed campaign to "liberate Iraq". The statement said Iraq is "under US, UK, and Iranian occupation".
The statement described the execution of Saddam as a crime and political assassination.
Abu Muhammad, a Baath party spokesman, said al-Douri was responsible for steering the party after Saddam's capture in December 2003.
He said: "Comrade Izzat has been leading the party's political and resistance factions since 2003, but it is a matter of protocol and internal regulation to appoint him officially as the party's secretary-general."
After Saddam's execution, Nuri al-Maliki, the Iraqi prime minister, invited the Baath party to join the political process in the country and open a new chapter.
|Al-Sadr wanted Saddam dead, saying he was |
responsible for the death of his father [AFP]
Abu Muhammad said: "We would like to tell Mr al-Maliki that our only mission is to continue armed struggle until we get him and his masters [the US] out of our country.
"The martyrdom of President Saddam would be just another boost to our people's resistance against his corrupt rule and foreign occupation."
Abu Muhammad further accused the Iraqi government and US authorities in Iraq of imposing a media blackout on Iraqis' reaction to the execution of Saddam.
He said: "Media outlets have been focusing on reactions in President Saddam's home town and few other Iraqi Sunni Arab cities, but we would like to say that people all over Iraq have been mourning the death of their legitimate president for two days.
"I have no sympathy for Saddam, but his life is not worth the lives of innocents that die daily in Baghdad"
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"In al-Shatra in the southern governorate of Dhu Qar, there have been clashes where angry citizens attacked the al-Sadr al-Mahdi Army and killed eight of them and injured dozens."
Muqtada al-Sadr, the Shia leader, and his supporters had called for Saddam's execution. They hold him responsible for the death of al-Sadr's father in a car crash in 1999. Iraqi authorities at the time had denied any involvement in the elder al-Sadr's death.
In another development, Jordan's Baath party said it will organise a symbolic funeral in Amman on Friday.
On Monday, Ahmed al-Najdawi, a spokesman, said the party has been receiving condolences from Jordanian political parties and people for the last two days.
He said: "Politicians and people from all backgrounds have expressed their sorrow for the loss of President Saddam Hussein.
"Today there was sit-in at the trade unions' compound to protest against the crime of assassination committed by the occupation authorities in Iraq. Mrs Raghad, President Saddam's daughter, attended the event."
It was Raghad's first public appearance after the death of her father, and was her first public participation in public political activity since she was offered asylum in Jordan in 2003.