Armed men have ambushed a convoy of trucks carrying construction material to a US military north of Baghdad, killing four Iraqi drivers.
As violence continued on Sunday, a day after 20 people, including a US soldier, were killed in a spate of bombings and shootings, the Iraqi drivers were not the only victims of violence.
In a roadside bombing in northern Iraq, a police general was killed, said police Lieutenant Khalid al-Obaidi, adding that the ambush occurred near Nibaie, about 55km north of the capital.
The area has been the scene of several ambushes and roadside bombings in the past few days.
Also in Baghdad, a car bomb exploded late on Sunday afternoon near a Shia political office in the Jadiriyah district, killing two people, including one police officer, and wounding five, three of them police, officials said.
Minutes later, a bomber detonated explosives strapped to his body at an Iraqi army checkpoint protecting the Defence Ministry in central Baghdad.
Three civilians were wounded, police said.
Three executed
Furthermore, police found bodies of three men - bound, blindfolded and shot execution-style - in Baghdad's Shia stronghold of Sadr City on Sunday.
They appeared to be the latest victims of sectarian tit-for-tat killings, which have sharpened religious tensions as Iraqi politicians try to form a national unity government following the December parliamentary elections.
In northern Iraq, police Brigadier-General Hatim Khalaf and his driver were killed when a roadside bomb exploded 32km southwest of Kirkuk, police said.
Khalaf was the chief of the operations centre for the police in Kirkuk, headquarters of Iraq's northern oil-producing centre.
Two police officers also were wounded in a roadside bombing on Sunday in Falluja, the former anti-US stronghold 65km west of Baghdad.
In other news, more than 1000 students at Diyala University marched through the streets of Baquba to the governor's office on Sunday to protest against the caricatures of the Prophet Muhammad, which first appeared in a Danish newspaper in September.
The students were also protesting against a recent video showing British forces beating Iraqi youths during a January 2004 protest in Amarah.
Signs read "We sacrifice our souls and blood for Islam" and other religious slogans.
Wreckage found
Search crews have found the wreckage of a German plane in northern Iraq with six Germans and an Iraqi on board dead, according to an official.
The plane was en route to Iraq from Azerbaijan carrying five Germans and an Iraqi - employees of a Bavarian construction company - when it went missing during stormy weather on Thursday night over the rugged area near the border between Iran and Iraq.
Shahou Mohammed, the regional administrator in Sulaymaniya, said the wreckage was found near Boushin, northeast of Sulaymaniya, 260km northeast of Baghdad, after villagers reported the crash.
He said searchers, who were in radio contact with him, found six bodies on board.
In another development, Australia said on Sunday it would probably not withdraw its troops protecting Japanese reconstruction teams in Iraq even if the Japanese leave.
Brendan Nelson, Australia's defence minister, said Australian forces could redeploy elsewhere in Iraq if the that if the Japanese humanitarian teams left after May.
Australia has about 1320 troops in Iraq and the Middle East, including about 460 soldiers guarding the Japanese in the southern province of Muthanna.
PHOTO CAPTION
An Iraqi walks near a burning truck on a roadside after an attack on a highway west of Baghdad February 15, 2006. (REUTERS)