Attackers firing rockets and mortars into the heavily fortified Green Zone have significantly improved their aim in the past three months, a top U.S. commander said Thursday.
The more skillful assault was linked to training in Iran, according to Lt. Gen. Ray Odierno.
He said networks continue to smuggle powerful roadside bombs and mortars across the border from Iran despite Tehran's assertions that it supports stability in Iraq.
His remarks came two days after the U.S. and Iranian ambassadors to Iraq met in Baghdad and agreed to establish a security committee to jointly address the violence amid Washington's allegations that Tehran is fueling the violence by Shiite militias.
Odierno said the military also believes training of extremists is being conducted in Iran.
"One of the reasons why we're sitting down with the Iranian government ... is trying to solve some of these problems," Odierno said at a news conference in the Green Zone, which is home to the U.S. Embassy and the Iraqi government headquarters.
"We have seen in the last three months a significant improvement in the capability of mortar men and rocketeers to provide accurate fires into the Green Zone and other places and we think this is directly related to training that is conducted in Iran," Odierno said. "So we continue to go after these networks with the Iraqi security forces."
Iran has denied the U.S. allegations about its activities in Iraq.
Attacks against the Green Zone, a sprawling complex along the Tigris River in the center of Baghdad, have increased in recent months, adding to the concern over the safety of key Iraqi and international officials and thousands of U.S. soldiers and contractors who live and work there.
Odierno, responsible for day-to-day activity in Iraq, expressed cautious optimism over a decline in the number of American troops killed this month.
At least 60 U.S. troops have died so far in July compared with more than 100 for the previous three months, based on figures The Associated Press compiled from military statements.
Odierno said it appeared that casualties had increased as U.S. forces expanded operations into militant strongholds — as part of the recent security operation to squash violence in the capital — but were going down as the Americans gained control of the areas.
"We've started to see a slow but gradual reduction in casualties and it continues in July," he said at a joint news conference with Iraqi military commander Maj. Gen. Abboud Qanbar. "It's an initial positive sign, but I would argue we need a bit more time to make an assessment whether it's a true trend."
Iraqis in Baghdad swept up debris from bloodstained pavement, a day after two suicide bombings killed at least 50 cheering, dancing, flag-waving Iraqis celebrating the national soccer team's semifinal victory in the Asian Cup tournament.
The attacks bore the hallmarks of Sunni militants who have fueled the violence tearing at the fragile fabric of Iraq for nearly four years. But these bombings, in parked cars less than an hour apart in separate corners of Baghdad, appeared designed to gain attention rather than target a particular sect.
The first attack was near an ice cream parlor on Wednesday, charring the interior of the corner store in the predominantly Sunni Mansour neighborhood in west Baghdad. At least 30 people were killed and 75 wounded, according to the Interior Ministry.
The second took place in the midst of dozens of vehicles filled with revelers near an Iraqi army checkpoint in the eastern district of Ghadeer, where an uneasy mix of Sunnis, Shiites and Christians live. At least 20 people died and nearly 60 were wounded, the ministry said.
The Iraqi commander blamed the bombings on terrorists and Sunni extremists upset with the unity on display as people of all religious backgrounds celebrated the win.
"But our people have proved to the world that they are unified no matter what terrorism does, and it was proven that terrorism has no religion and is the enemy to all people and the enemy of humankind," Qanbar said.
Violence also struck Iraqi security forces on Thursday, with a roadside bomb targeting a police patrol on the road between Hillah and Diwaniyah, killing five officers and wounding two as they were on their way home from an operation with U.S. forces, police said.
Diwaniyah, 80 miles south of Baghdad, has been the site of heavy clashes between U.S.-Iraqi security forces and Shiite militia fighters.
In political developments, Iraq's Vice President Tariq al-Hashemi's office said the moderate Sunni leader had met with U.S. Ambassador Ryan Crocker on Wednesday to discuss his political bloc's objections to the leadership of Prime Minister Nouri al-Maliki.
"The vice president confirmed that the absence of collective leadership and actual participation in running the country is one of the obstacles facing the political process in the country and that stands against reaching agreements ... on key laws," al-Hashemi's office said in a statement.
The meeting occurred on the same day al-Hashemi's Iraqi Accordance Front, which includes two hardline partners, suspended membership in the government, a bid that appeared timed to deepen disenchantment in Washington with the Shiite prime minister's faltering leadership.
The Iraqi Accordance Front, which has six Cabinet seats and 44 of 275 in parliament, gave al-Maliki a week to meet its demands or see ministers quit the 14-month-old government. Al-Maliki faces intense scrutiny in Washington, where Gen. David Petraeus, the U.S. commander in Iraq, and Crocker are required to report to Congress by Sept. 15 on progress in Iraq.
From NPR and Associated Press reports