Fertilizer from Turkey.

Detonator cord made in India.

Microprocessors made in the USA.

Islamic State militants have built a fast and effective supply chain for its making improvised explosive devices, one that is flowing underneath the radar of international rules designed to halt weapons sales, according to a new report.

The main components of the Islamic State's signature weapon — chemicals, fuses and cell phones — are not subject to many traditional export controls because they have viable commercial and industrial uses.

And it can take just a few weeks for many of those items to move from legal over-the-counter sales in neighboring countries to fully assembled weapons on the battlefield in Iraq and Syria, according to Conflict Armament Research, a London-based group that investigates the supply of weapons into armed conflicts.

"Perhaps the most significant finding of this report concerns the speed with which IS forces have been able to acquire IED components," the group concluded in a report released Thursday.

"The appearance of these components in possession of [Islamic State] forces, as little as one month following their lawful supply to commercial entities in the region, speaks to a lack of monitoring by national governments and companies alike."

The first-of-its-kind study examined dozens of IEDs and bomb-making facilities seized by anti-ISIS forces in Iraq and Syria.

Turkey is a "choke point" for many IED supplies, especially the key chemicals that have legitimate uses in agriculture and other industries, like ammonia nitrite, aluminum and petroleum jelly, the report said.

Often those products have documentation of legal sales in Turkey and are presumably exported illegally into Iraq and Syria.

Iraqi Kurdistan and the cities of Kirkuk and Erbil are often the last documented location for ISIS weapons supplies, according to the report.

The study linked at least 51 companies in 20 countries to the Islamic State supply chain. None of the companies contacted by the researchers admitted any intentional exports to Iraq or Syria or sales to ISIS operatives.

For example, investigators found several drums of aluminum paste at an ISIS bomb-making facility in Tikrit, Iraq, shortly after ISIS forces withdrew from the city in April 2014. Labels showed the material was manufactured in late 2014 in several counties, including Brazil, China and Romania, and then shipped to distributors in Istanbul.

The distributors, when contacted by the CAR investigators, said they do not export any products to Iraq or Syria.

Most of the detonator cords found at ISIS bomb factories were made in India and shipped to distributors in Turkey and Lebanon before ending up on the battlefield in Iraq and Syria.

Unlike the supply line used by the insurgents that U.S. troops faced in Iraq from 2003 to 2011, the current ISIS supply chain showed little involvement from Iran.

Yet some items are similar to those found during that period, when the Sunni Arab insurgency was known as al-Qaida in Iraq.

ISIS has used electronic chips, used for remotely detonating IEDs, made by an Arizona company, the report said. Prior research found the same company's microcontrollers were used by insurgents during Operation Iraqi Freedom, "which indicates some continuity, and possibly a technology transfer, between different groups in the Iraq conflict," the report said.