WARRI, Nigeria — Shell Nigeria said Thursday it has closed a 6,000-kilometer (3,700-mile) oil pipeline to repair leaks from oil theft.Shell recently threatened to close the Nembe Creek Trunk Line because of repeated sabotage. It carries about 150,000 barrels daily for Africa's biggest oil producer. Shell did not say how much oil has been lost through the leaks or how the closure may affect Nigeria's daily output of 2.2 million barrels a day.Spokesman Precious Okolobo said Thursday the line was shut Sunday for repairs to several "crude theft points." He said they hoped to reopen it as soon as possible.Thefts of up to 200,000 barrels a day are blamed on villagers who have lost arable land and fishing grounds to oil spills and militants demanding a more equitable share of oil revenues. But the biggest offenders are believed to be politically-connected syndicates who sell the crude on the international market.Human rights activists charge Shell sometimes blames sabotage for leaks caused by erosion on aging pipelines to avoid compensating villagers. But the Nembe Creek line was replaced by Shell in 2010 at a cost of $1.1 billion.