International troops and Afghan police seized 250 tons of ammonium nitrate fertilizer — enough to make up to a couple hundred roadside bombs, the Taliban's most lethal weapon in what has been the deadliest year of the war, NATO announced Tuesday.

Separately, video footage emerged of insurgents brandishing what appears to be limited stocks of U.S. ammunition in a remote area of eastern Afghanistan where eight Americans died in a battle last month.

NATO officials hoped Sunday's raid in the southern city of Kandahar would hurt Taliban militants, whose homemade bombs have become the biggest killer of U.S. and allied troops.

Acting on a tip, international forces and Afghan police discovered 1,000 100-pound bags of ammonium nitrate fertilizer and 5,000 parts for roadside bombs in a warehouse, the military said. After the initial find Sunday, an additional 4,000 100-bags of fertilizer were found in a nearby compound. The joint forces also made 15 arrests.

The seizure included enough fertilizer to make dozens to a couple of hundred roadside bombs, said John Pike, director of the military think tank Globalsecurity.org.

The insurgents have been successful manufacturing homemade bombs from materials such as fertilizer, which is easily available in agricultural areas of the south.

In a country awash in weapons after 30 years of war, the Taliban also appear to have little trouble obtaining rifles, machine guns, rocket-propelled grenades and other ordnance, some of which may be bought on Asian black markets.

There is not much evidence to suggest that the Taliban rely on weapons captured or stolen from NATO forces or that they even need to shore up their own stockpiles, Pike said.

"I don't think they have a shortage of Kalashnikovs," he said. "I think it's probably more often a case of it leaking out of the Afghan army. I think the Afghan National Army has a high AWOL rate and everything's for sale in Afghanistan."

The footage of insurgents handling weapons, including anti-personnel mines with U.S. markings on them, was broadcast Tuesday on Al-Jazeera.

Insurgents could employ the ammunition against U.S. and Afghan forces, though the amount shown was not extensive. Still, Taliban propagandists will no doubt use the footage to encourage their supporters.

The insurgents claimed the weapons were from remote outposts in Nuristan province that were abandoned after the battle that killed eight Americans, according to Al-Jazeera.

Tech. Sgt. Angela Eggman, a NATO spokeswoman, said it wasn't clear from the video where or when insurgents obtained the items. U.S. forces closed outposts in the mountainous Kamdesh district of Nuristan province in early October.

"Before departing the base, the units removed all sensitive items and accounted for them," she said.

Nuristan's provincial police chief Gen. Mohammad Qassim Jangulbagh disagreed, saying, "The Americans left ammunition at the base."

The U.S. destroyed most of the ammunition, but some of it fell into the hands of insurgents, Jangulbagh said.

Farooq Khan, a spokesman for the Afghan National Police in Nuristan province, also said U.S. forces left arms and ammunition when they moved from the area, which he said is now in insurgent hands.

The Pentagon said the outposts in Nuristan were on a list of far-flung bases that U.S. war commanders had decided were not worth keeping. That decision, the Pentagon said, was on the books before the assault — part of plans by top U.S. commander in Afghanistan Gen. Stanley McChrystal to shut down such isolated strongholds and focus on more heavily populated areas.

Meanwhile, NATO said a U.S. service member was killed Tuesday by a roadside bomb in Helmand province. The military provided no other details.