* Army says sorry, no orders given, blames "altercations"
* Thousands in Tahrir Square had called for new cabinet
* Egyptian investigators detain former information minister
(Adds military releases all protesters detained)
By Marwa Awad and Dina Zayed
CAIRO, Feb 26 (Reuters) - Soldiers used force on Saturday to break up a protest demanding more political change in Egypt in the toughest move yet against demonstrators who accused the country's military rulers of "betraying the people".
Protesters said the soldiers had moved against them after midnight, firing in the air and using sticks to break up the remnants of a demonstration urging the military to enact deeper reforms including a complete overhaul of the cabinet. The Supreme Council of the Armed Forces, which has been ruling Egypt since President Hosni Mubarak stepped down in the face of a mass uprising, apologised, said there had been no order to assault the protest and the incident was unintentional.
Protesters detained overnight would be released, it said, without stating how many of them there were. It said "infiltrators" had thrown bottles and rocks at soldiers.
"What happened last night was ... the result of unintentional altercations between the military police and the children of the revolution," the council said on a Facebook page that has become a main tool in its public relations effort. Ashraf Omar, a demonstrator, said soldiers had used tasers and batons against the protesters. "I thought things would change. I wanted to give the government a chance but there is no hope with this regime," he said.
The military council has promised constitutional changes leading to free and fair elections within six months. The judicial council tasked with drafting the constitutional reforms is expected to announce its proposals soon. As it manages domestic affairs for the first time in decades, the military also wants Egyptians to get back to work to revive an economy drained by weeks of turmoil unleashed by the mass uprising that toppled Mubarak on Feb. 11.
Thousands of people had gathered in Tahrir Square on Friday to press broader demands including the replacement of the prime minister, who was appointed by the ousted president in the last weeks of his rule and had long served his administration.
As day broke, a few dozen protesters left in the square flagged down motorists, telling them that the army had attacked the protest. A number of the activists held aloft signs declaring "the army betrayed the people".
One taxi driver remonstrated with a protester, telling him: "The people can't find food to eat." His view reflected the feelings of those Egyptians who believe continued protests are obstructing a return to normality.
FOR NOW, MILITARY APPEARS HESITANT ON FURTHER REFORM
Witnesses said they saw several protesters fall to the ground but it was not clear if they were wounded and if so, how seriously. Protesters were heard yelling and shouting as they were chased down side streets surrounding Tahrir Square. The protesters want the resignation of Prime Minister Ahmed Shafiq as well as the removal of other ministers associated with Mubarak's rule and the immediate release of remaining political detainees. A partial cabinet reshuffle has not satisfied them.
Opposition groups want a complete break with the past in the run up to democratic elections promised by the military. Having committed to constitutional changes and democratic elections, the military appears reluctant to enact further reforms, a Western diplomat said. The military council appears to want to leave further reforms to an elected civilian government, the diplomat added.
The military appeared to want to "get out from under the obligation" of government, the diplomat added. An anti-corruption campaign targeting prominent figures in Mubarak's era is one of the clearest signs yet of a break with the past. The foreign ministry has instructed governments overseas to freeze the assets of Mubarak and his family.
Several former ministers and businessmen linked to the ruling party are also under investigation.
In the latest case, investigators have ordered the detention of former Information Minister Anas el-Fekky for 15 days on charges of profiteering and wasting public funds, the state news agency MENA said on Saturday. (Additional reporting by Yasmine Saleh and Mohamed Abdellah; Writing by Tom Perry; Editing by Caroline Drees)