Alauddin deployed an extensive network of "Munhiyans" (spies, secret police) who would monitor the "mandi" and had the power to seize anyone trying to buy or sell anything at a price different than the official controlled prices. Those found violating these "mandi" rules were severely punished, such as by cutting out their flesh. Taxes collected in form of seized crops and grains were stored in sultanate's granaries. Over time, farmers quit farming for income and shifted to subsistence farming, the general food supply worsened in north India, shortages increased and Delhi Sultanate witnessed increasingly worse and extended periods of famines. The Sultan banned private storage of food by anyone. Rationing system was introduced by Alauddin as shortages multiplied; however, the nobility and his army were exempt from the per family quota-based food rationing system. The shortages, price controls and rationing system caused starvation deaths of numerous rural people, mostly Hindus. However, during these famines, Khalji's sultanate granaries and wholesale "mandi" system with price controls ensured sufficient food for his army, court officials and the urban population in Delhi. Price controls instituted by Khalji reduced prices, but also lowered wages to a point where ordinary people did not benefit from the low prices. The price control system collapsed shortly after the death of Alauddin Khalji, with prices of various agriculture products and wages doubling to quadrupling within a few years. The tax system introduced during the Khalji dynasty had a long term influence on Indian taxation system and state administration,  Within Sultanate's capital city of Delhi, during Alauddin Khalji's reign, at least half of the population were slaves working as servants, concubines and guards for the Muslim nobles, amirs, court officials and commanders. Slavery in India during the Khalji dynasty, and later Islamic dynasties, included two groups of people - persons seized during military campaigns, and people who defaulted on their taxes. The institution of slavery and bondage labor became pervasive during the Khalji dynasty; male slaves were referred to as "banda", "qaid", "ghulam", or "burdah", while female slaves were called "bandi", "kaniz" or "laundi". Alauddin Khalji is credited with the early Indo-Mohammedan architecture, a style and construction campaign that flourished during Tughlaq dynasty. Among works completed during Khalji dynasty, are Alai Darwaza - the southern gateway of Qutb complex enclosure, the Idgah at Rapri, and the Jamat Khana (Khizri) Mosque in Delhi.