after weeks of delay, the u.s. government presented it's evidence that iran was supplying weapons to groups in iraq that attack u.s. forces.
it's really hard to figure out exactly what was presented as no copies of the actual presentation were released. the reporters who attended had their cell phones taken away so they couldn't take pictures for an independent analysis of the serial numbers. so instead we're left with the few photos that were released as part of the briefing. the the telegraph published a photo of one of the allegedly incriminating serial numbers, but as sean-paul points out the numbers and letters visible on the bomb are not arabic/farsi characters. instead the bomb the u.s. is claiming was manufactured in iran was actually manufactured in pakistan by the pakistan ordnance factories.
...the LA times has a link (click on the "photo gallery: US evidence" button on the left just under the picture) to some other photos of the munitions--like this one and this one. but like the telegraph photo, neither serial number is in arabic/farsi script.
so, to summarize, all the photographs of serial numbers that i can find, none have serial numbers using arabic/farsi characters. and at least one of the armaments the u.s. is calling "iranian manufactured" was clearly manufactured in pakistan.
on top of that, even if the arms were manufactured in iran where is the evidence that they were sent to iran with the blessings of the iranian government?
i guess that's why we've been getting all these reports that the delays in releasing this information was because of misgivings by people in the intelligence community that the case that iran was behind iraqi violence was weak and was being overstated.