The US on Wednesday announced sanctions on nearly 300 companies and individuals, including in China and the United Arab Emirates, for alleged support of Russia’s invasion of Ukraine.

According to the US Treasury Department, the Chinese firms include Hong Kong-based Finder Technology Ltd., which is accused of exporting 293 shipments of drone parts and other electronics, Juhang Aviation Technology Shenzhen Co., which is accused of providing Russia with drone propellers, signal jammers, sensors and engines; and Zhongcheng Heavy Equipment Defense Technology Group Co. Ltd., which is accused of supplying the paramilitary Wagner Group.

Treasury also targeted for the first time manufacturers and suppliers of cotton cellulose and nitrocellulose, which are precursors for making gunpowder, rocket propellant and other explosives. A combination of Russian and Chinese companies were sanctioned for being involved in the trade of those materials.

The move comes shortly after Treasury Secretary Janet Yellen warned Chinese officials the US would take action against any firms that helped Russia’s military procurement efforts.

Yellen said in a statement Wednesday that the sanctions, along with recently enacted additional funding for Ukraine, mean that the country has a “critical leg-up on the battlefield.”

She had foreshadowed parts of Wednesday’s announcement in remarks April 8 in Beijing, when she said that “companies, including those in the PRC, must not provide material support for Russia’s war and that they will face significant consequences if they do.”

Yellen had also cautioned that day that the US might sanction Chinese banks that were involved in “significant transactions that channel military or dual-use goods” to Russia. However, no financial institutions based in China were named in Wednesday’s announcement.

China-based Hengshui Heshuo Cellulose Co. Ltd. and Hengshui Yuanchem Trading Ltd. are accused of shipping large quantities of nitrocellulose to Russia.

The Treasury Department also sanctioned UAE-based Albait Al Khaleeje General Trading LLC for acting as a conduit for sanctioned goods to Russia. The company, which advertises itself as an auto parts exporter, has been involved in more than 6,800 shipments to Russian customers, according to the department.

In addition, the US expanded restrictions against Russia’s Arctic LNG 2 project, including a Singapore-based company, a Hong-Kong-based entity and almost two dozens vessels. US has also designated 12 entities within the Sibanthracite group of companies, one of Russia’s largest producers of metallurgical coal. A popular budget airline Pobeda was also sanctioned.

The State Department determined that Russia used the chemical weapon chloropicrin against Ukrainian troops and levied sanctions against companies and individuals it says have aided Russia’s chemical and biological weapons programs in violation of sanctions and other restrictions.

The department also sanctioned three individuals in connection with the death of Russian opposition leader Alexey Navalny at a Russian prison.