BAGHDAD (AP) – Two Sunni leaders who took public stances against al-Qaida in Iraq were attacked Saturday, in a sign the terror network may ramp up retaliation against local chiefs who oppose it.

Meanwhile, a powerful roadside bomb killed the governor and police chief of a southern province torn by fierce fighting between Shiite factions.

The flurry of attacks hinted at the complex challenges facing Iraq, from both Shiite militias and Sunni extremists, who often target not just Americans but also their own sects in vicious internal battles.

Militants bombed the northern Baghdad home of a moderate and highly regarded Sunni cleric, Sheik Wathiq al-Obeidi, who had recently spoken against al-Qaida. He was seriously wounded and three relatives were killed.

The governor, Khalil Jalil Hamza, and the police chief, Maj. Gen. Khalid Hassan, were killed along with their driver and a bodyguard. Hassan had been on the job only a week, officials said.

The bomb that killed the governor and police chief struck in Qadisiyah province.

In the second attack, a local tribal leader in Albu Khalifa, a village west of Baghdad, was gunned down by militants who broke into his home Saturday. Sheik Fawaq Sadda’ al-Khalifawi had recently joined the anti-al-Qaida alliance in Anbar.

The attacks came as Iraq’s politics remain stalled between the Shiite-led government and Sunnis suspicious that the government favors Shiite militias backed by Iran.

province as the two traveled back to the capital of Diwaniyah from a funeral.

Diwaniyah has been the site of heavy clashes between U.S.-Iraqi security forces and Shiite militia fighters. The area also has seen a rise in internal rivalries between militia forces.

Authorities imposed an indefinite curfew after the deaths, and al-Maliki ordered an investigation and urged citizens to show restraint.

The governor was a member of the influential Supreme Islamic Iraqi Council, a group led by Shiite politician Abdul-Aziz al-Hakim. His loyalists dominate the police and have engaged in fierce fighting with the Shiite Mahdi Army for control of the oil-rich south.

In all, at least 33 people were killed or found dead nationwide, including a police officer and a woman who were struck by separate roadside bombs in northern Iraq.

Separately, the U.S. military on Saturday reported the death of a soldier in Tikrit in a non-combat incident.