BAGHDAD (AP) _ An F-16 fighter jet crashed Friday in Iraq, the Air Force reported, in the first such loss in more than six months. The statement said the crash was an accident, but did not say where the plane went down or what happened to the pilot.
Separately, the U.S. military announced the deaths of five American soldiers. In a surprise visit to Iraq, Defense Secretary Robert Gates offered support for the top U.S. commander here and denied that the military was offering overly optimistic assessments of the war.
``It's a very mixed picture,'' Gates told reporters on his plane when asked whether the military and Gen. David Petraeus were realistic about the violence that continues in Baghdad even after the number of U.S. troops has been increased over the past few months. Senate Majority Leader Harry Reid has questioned whether the top commander in Iraq was being candid.
The loss of an F-16, a workhorse warplane in the Iraq war, is rare. One crashed last Nov. 27 in the western province of Anbar, killing the pilot. The jet that crashed shortly after midnight on Friday was deployed to the 332nd Air Expeditionary Wing at Balad Air Base, 50 miles north of Baghdad.
``The cause of the accident is under investigation,'' said the statement from the Central Command Air Forces, which provided no further details.
The Iraqi prime minister imposed an indefinite curfew on Basra, Iraq's second largest city and gateway to the Persian Gulf, after bombers leveled a Sunni shrine just outside the city. A similar ban already in place in Baghdad was extended another day, until dawn Sunday, government spokesman Ali al-Dabbagh said.
Gunmen armed with rocket-propelled grenades attacked the Talha Bin al-Zubair shrine about 13 miles outside Basra late Thursday, partially damaging the building, police said. They returned early Friday, planting bombs inside the structure and exploding it completely, police said. No injuries were reported.
Gen. Ali al-Mussawi, a top Basra security official, said the bombers were disguised as cameramen who asked guards for permission to film inside the shrine. Minutes after they left, a huge explosion rocked the building, destroying the dome and minaret, he said.
The guards were detained afterward for questioning, al-Mussawi said.
Talha Bin al-Zubair was one of the Prophet Muhammad's companions and commands high respect among Sunnis. The shrine was renovated in late 1990s, during Saddam Hussein's rule. Sunni pilgrims from India, Pakistan and Turkey frequently visit the shrine.
Prime Minister Nouri al-Maliki's office called the bombing of the Sunni shrine another of the ``crimes aimed at sowing sedition and inflaming sectarian strife among the people.''
Three of the U.S. soldiers were killed when a bomb exploded near their vehicle Thursday during operations in Kirkuk province, in northern Iraq, the U.S. military said in a statement. Another soldier was wounded in the blast.
A fourth soldier was killed by small arms fire the same day in Diyala province, northeast of Baghdad, another statement said. And another soldier died Wednesday in a non-combat related incident, which the military said it was investigating.
A Baghdad-wide clampdown continued Friday, and the curfew was extended to a third day after suspected al-Qaida bombers blew the minarets off a sacred Shiite shrine and stoked fears of a bloody sectarian backlash.
At least four Sunni mosques were attacked within hours of the Shiite shrine blasts in Samarra on Wednesday, and police in Basra reported four people killed in retaliatory violence there.
Thursday's barrage of rockets and mortars included one that hit on a street close to the Iraqi parliament less than a half hour before Deputy Secretary of State John Negroponte passed nearby.
The attack again showed militants' resilience _ including their ability to strike the heavily protected zone _ despite a U.S.-led security crackdown across the city that began four months ago. But officials paid much closer attention to any signs that Shiites could unleash another wave of retaliation against Sunnis for the explosions at the Askariya mosque compound in Samarra.
The first attack on the site in February 2006 sent the country into a tailspin of sectarian violence that destroyed Washington's hopes of a steady withdrawal from Iraq. On Wednesday, bombers toppled the two minarets that stood over the ruins of the mosque's famous Golden Dome about 60 miles north of Baghdad.
Meanwhile, insurgents linked to al-Qaida released a videotape showing the execution-style deaths of 14 Iraqi soldiers and policemen after the expiration of a 72-hour deadline for the Iraqi government to meet their demands. In an earlier video, the group demanded the release of all female prisoners in Iraqi prisons.
The killings took place in what looked like a rural area, with a grass field and several tall eucalyptus trees. A small wooden shack stood in the background.
The authenticity of the 1 1/2 minute video could not be verified, but it appeared on a Web site commonly used by Islamic militants and carried the logo of the Islamic State of Iraq's media production wing, al-Furqan.
The U.S. soldier deaths announced Friday brought to at least 3,520 the number of American military personnel who have died since the beginning of the Iraq war in March 2003, according to an Associated Press count. The figure includes seven military civilians. At least 2,889 died as a result of hostile action, according to the military's numbers.