Sudan banned the import of many types of goods including furniture, animals and food products on Sunday.
Analysts blame government over-spending, increased debt and a neglect of core industry and agriculture for Sudan's growing economic crisis as inflation soars and the Sudanese pound weakens.
Last week Khartoum cut subsidies on all petroleum products and sugar, adding it would eventually remove all support. Sudan produces some 500,000 barrels per day of oil, most of which comes from the south where voting began on Sunday on independence from the north which it has fought for decades.
"According to this directive, all traders must stop all procedures relating to the imports of the aforementioned goods starting today," the central bank said in a statement.
The banned goods include live animals and animal products, sweets, furniture, silk, real and fake leather, trees, most plants and flowers, plastic products, pasta, mineral water, tobacco for water pipes, flour products, fresh and frozen meat and dairy products.
Khartoum had already taken measures to restrict imports and few banks were able to offer letters of credit. The stringent moves are likely to hit traders hard who profited from the boom years when the government allowed massive imports to compensate for a decline in local output.
The capital's normally fully stocked supermarkets were already looking emptier on Sunday as import restrictions and hikes in customs duties imposed late last year took their toll.
Small to medium-sized businesses will be worst hit, saying the moves had come without warning and they could not turn from being importers to exporters overnight and without capital.
Sudan blames the problems on the global financial crisis and speculation ahead of the referendum on secession. But analysts say the people are paying the price of their past spendthrift policies.
In November the Central Bank effectively devalued the Sudanese pound in the market by matching the black market rate in official trade, a move it hoped to row back on once foreign exchange liquidity in the market improves.
On Sunday bank governor Sabir Hassan said in a separate statement that the policy had brought more hard currency into official trade and that he was aiming for a rate of 2.70 Sudanese pounds to the U.S. dollar. One U.S. dollar buys just over three Sudanese pounds on the parallel market.