An Indian company shipped $1.4 million worth of an explosive compound with military uses to Russia in December, according to Indian customs data seen by Reuters, despite US threats to impose sanctions on any entity supporting Russia’s Ukraine war effort.

According to the sources, one of the Russian companies listed as receiving the compound, known as HMX or octogen, is the explosives manufacturer Promsintez, which an official at Ukraine’s SBU security service said has ties to Moscow’s military.

The official said that Ukraine launched a drone attack in April against a Promsintez-owned factory.

The other Russian company is a subsidiary of Spanish explosives manufacturer Maxam, which is itself controlled by New York-based private equity firm Rhone Capital.

On the other hand, US government has identified HMX as “critical for Russia’s war effort” and has warned financial institutions against facilitating any sales of the substance to Moscow.

According to the Pentagon’s Defense Technical Information Center and related defense research programs, HMX is widely used in missile and torpedo warheads, rocket motors, exploding projectiles and plastic-bonded explosives for advanced military systems.

The HMX sale to Russian firms has not been previously reported.

Russian defense manufacturers have been working around the clock for the past several years to sustain President Vladimir Putin’s war in Ukraine, which intensified with Russia’s full-scale invasion of its neighbor in 2022.

India, which has recently forged closer ties with the United States in an effort to counterbalance China’s growing influence, has not abandoned its longstanding military and economic ties with Moscow.

India’s trade with Russia especially its purchases of Russian oil has remained robust, even as Western nations have tried to cripple Russia’s war economy with sanctions.

US President Donald Trump threatened earlier in July to hit nations with a 100% tariff if they continued purchasing Russian crude.

The US Treasury Department has the authority to sanction those who sell HMX and similar substances to Russia, according to three sanctions lawyers. HMX is known as a “high explosive,” meaning it detonates rapidly and is designed for maximum destruction.

Reuters has no indication that the HMX shipments violated Indian government policy. One Indian official with knowledge of the shipments said that the compound has some limited civilian applications, in addition to its better-known military uses.

India’s foreign ministry said in a statement: “India has been carrying out exports of dual-use items taking into account its international obligations on non-proliferation, and based on its robust legal and regulatory framework that includes a holistic assessment of relevant criteria on such exports.”

The US State Department did not comment on the specific shipments identified by Reuters but said it had repeatedly communicated to India that companies doing military-related business are at risk of sanctions.

“India is a strategic partner with whom we engage in full and frank dialogue, including on India’s relationship with Russia,” a spokesperson said.