Protests at Libyan oilfields have cost 250,000 barrels per day (bpd) in lost production, Oil Minister Abdelbari al-Arussi said on Monday. \"Libya\'s production has been affected recently by sit-ins which have stopped production and caused a deficit of 250,000 bpd,\" Arussi said in comments carried by the official LANA news agency. Demonstrations have been held at the terminals at Al-Harriga in Tobruk and Zueitina in the east, and at the Al-Fil oilfield in Ubari in the south, Arussi said. The minister gave no details of the reasons for the protests, but said that \"these protests are affecting Libya\'s economy, which depends on oil and gas resources\". He warned against \"any disruption of this sector that could lead to a delay in the country\'s development\". Libya\'s economy relies heavily on hydrocarbons, which account for more than 80 percent of its GNP and up to 97 percent of its exports. Before the 2011 uprising that toppled veteran dictator Moamer Kadhafi, production reached 1.6 million bpd. It dropped to almost nothing during the fighting. But a few months after the overthrow of the Kadhafi regime in October 2011, production had nearly returned to its pre-uprising level. Arussi also announced the formation of two new oil companies in the south of the country. \"One of the companies, which will refine, will be based in Ubari and will have a capacity of between 30,000 and 50,000 bpd,\" Arussi said. He added that \"the second company, for exploration, drilling and exporting oil and gas, will be created in Sebha\", also in the far south. Both firms will be subsidiaries of the state-owned Libyan National Oil Company, he said. Africa\'s fourth largest oil producer, Libya imports 70 percent of its refined petroleum products needs.