Indore is the commercial capital of Malwa region and Madhya Pradesh as state. Malwa is one of the world's major opium producers. This crop resulted in development of close connections between the economies of Malwa, the western Indian ports and China, bringing international capital to the region in the 18th and 19th centuries. Malwa opium was a challenge to the monopoly of the British East India Company, which was supplying Bengal opium to China. This led the British company to impose many restrictions on the production and trade of the drug; eventually, opium trading was pushed underground. When smuggling became rife, the British eased the restrictions. Today, the region is one of the largest producers of legal opium in the world. There is a central, government-owned opium and alkaloid factory in the city of Neemuch. Nevertheless, there is a still a significant amount of illicit opium production, which is channelled into the black market. The headquarters of India's Central Bureau of Narcotics is in Gwalior. The Rajputana-Malwa Railway was opened in 1876.