Chennai, Security agencies have seized another Pakistan-bound consignment, consisting of internationally banned chemicals used for tear gas and riot control agents, from China at a port in Tamil Nadu, officials said here on Thursday.

According to officials, Pakistan is allegedly working on an offensive chemical and biological warfare program with the help of its "all-weather friend" China.

Officials said the Chinese company, Chengdu Shichen Trading Co. Ltd, had sent a consignment of "orthochlorobenzylidene malononitrile" to Rohail Enterprises, a Rawalpindi-based defense supplier.

The shipment, weighing around 2,560 kg, was stored in 103 drums of 25 kg each and loaded onto a Hyundai Shanghai transport vessel (sailing under the flag of Cyprus), on April 18, 2024, at the port of Shanghai, China, they said.

The Karachi-bound ship arrived at the port of Kattupalli (Tamil Nadu) on May 8, 2024.

Customs authorities, in a routine check, detained the consignment because the name of the chemical was listed in India's export control list, 'SCOMET', as a controlled substance, officials said.

After seeking help from experts and investigating the chemical, it was discovered to be orthochlorobenzylidene malononitrile (CS), a substance included in the Wassenaar Agreement list.

While India is a signatory to the Wassenaar Agreement, China and Pakistan are not.

The consignment of chemicals was subsequently seized under the provisions of the Customs Act 1962 and the Weapons of Mass Destruction and Delivery Systems (Prohibition of Unlawful Activities) Act 2005.

In March, security agencies at Mumbai's Nhava Sheva port intercepted and seized a ship consignment from China bound for Karachi after it was found to be carrying a dual-use consignment linked to nuclear and missile programs ballistic missiles of Pakistan.