The Nigerian Navy says it destroyed 260 illegal oil refineries and burned 100,000 tons of contraband fuel to try to halt oil thefts bedeviling the economy of Africa’s biggest petroleum producer. Commanding officer Capt. Musa Gemu said sailors of the NNS Delta destroyed the refineries in the Warri South-West area of southern Delta region Friday night and arrested five suspects. He spoke Saturday night. Similar missions in the past have failed to slow estimated daily thefts of 200,000 barrels worth more than $20 million. Critics and analysts say most is stolen by politically-connected criminal cartels for sale on the international market. The small-time criminals targeted in such attacks can reconstruct crudely built sites in days. Shell Nigeria, the biggest operator, says it lost $1 billion to oil thefts in 2013.