Baghdad, Iraq ? U.S.-led forces turned over control of Iraq’s military command to the Shiite-led government Thursday, a key step toward the eventual withdrawal of foreign troops.

But the ceremony in the heavily fortified Green Zone only transferred authority for one of Iraq’s 10 divisions and its small air force and navy, and it remained unclear how quickly Iraqi forces would be prepared to take over security.

A legislative session nearby, meanwhile, degenerated into a shouting match as Sunni Arabs accused the majority Shiites of seeking to carve Iraq into sectarian enclaves.

Parliament Speaker Mahmoud al-Mashhadani interrupted a session after a draft bill submitted by the largest Shiite party led to accusations from Sunni Arabs that they were trying to divide Iraq. A live broadcast from parliament was pulled off the air amid acrimonious debate.

Sunni Arab legislator Saleh al-Mutlaq threatened his people “will not stay in a parliament that leads to the division of Iraq” and threatened to boycott any session that sought to approve such legislation.

The concept of federalism is enshrined in the new Iraqi constitution, and the Kurds in the north already have their own autonomous region. However, special legislation and a referendum would be needed to establish a federation comprised of autonomous regions.

Iraqi Prime Minister Nouri al-Maliki, left, takes a pen from top U.S. commander in Iraq, Gen. George Casey, after signing a document at a ceremony in Baghdad, Iraq, that puts the Iraqi prime minister in direct control of the country's military. Coalition forces handed over control of Iraq's armed forces command to the government Thursday, a move U.S. officials hailed as a crucial milestone on the country's difficult road to independence.

Both the north and mainly Shiite south are rich in oil, and Sunni Arabs could end up squeezed into Baghdad and Iraq’s western provinces, which have no resources. Many Sunnis fear that federalism will lead to the breakup of the country.

On Thursday, Shiite Prime Minister Nouri al-Maliki signed a document taking control of Iraq’s small naval and air forces and the 8th Iraqi Army Division, based in the south.

The top U.S. general in Iraq, George Casey, promised to “continue to fight with you to protect the Iraqi people wherever they are threatened.”

“Today is an important milestone, but we still have a way to go,” Casey said during the ceremony.

Attacks across Iraq killed at least 25 people. In Baghdad, six bombings – including three by suicide car bombers – killed at least 17 people.

The U.S. military command also said two soldiers and a Marine were killed Wednesday in separate incidents. One soldier and the Marine died in Anbar province west of Baghdad and the other soldier was killed near Hawija, 150 miles north of the capital.