BAGHDAD (AP) - Iran's commitments to stem the flow of weapons and explosives into Iraq ``appear to be holding up'' and have contributed to a sharp drop in roadside bombs across the country, a U.S. general said Thursday.
Major General James Simmons, a deputy corps commander, said that in October, U.S. forces logged 1,560 cases in which bombs were either found and exploded.
That compared with 3,239 incidents last March, he said. The October figure was the lowest since September 2005, he added.
Last August, Iranian officials promised visiting Iraqi Prime Minister Nouri al-Maliki that they would stem the flow of weapons and ammunition smuggled to extremists in Iraq, according to Iraqi authorities.
Since then, U.S. military officials have reported finding fewer ``explosively formed penetrators,'' a particularly deadly form of roadside bomb they believe come from Iran.
``We believe that the commitments that the Iranians have made appear to be holding up,'' Simmons said.
Iranian officials have publicly denied smuggling weapons to Shiite extremists. But U.S. authorities insist penetrator bombs are the signature weapon of Shiite militants.
Simmons said that penetrator bombs were still being found in Iraq but they appeared to have entered the country months ago.
U.S. authorities said penetrators were used in an attack Wednesday against a U.S. Stryker vehicle near an entrance to the Green Zone, killing one American soldier and wounding five others. Iraqi police said two Iraqi civilians also were killed.
It was the first major attack against a U.S. military vehicle in that area in the last four or five months, Simmons said.
Simmons said the vehicle was struck by ``an array'' of penetrators. The attack occurred in one of the most heavily protected areas of the capital, raising questions how the explosives could have been planted without collusion from Iraqi police or soldiers.
The general said U.S. and Iraqi authorities were investigating the attack.
Simmons said U.S. authorities also were encouraged by an increase in tips from Iraqi citizens about weapons caches, which he interpreted as a sign the public was turning against both Shiite and Sunni extremists.
``We had found more caches by May of this year than in all of 2006,'' he said.
Simmons said most of the roadside bomb attacks recently had occurred in Sunni areas north of Baghdad.