Anglo-Dutch Shell said that approximately 61,000 barrels of crude oil were spilled in Nigeria last year, largely due to the activities of armed militants in the Niger Delta.

According to Shell, saboteurs spilled almost 48,000 barrels of oil in 140 incidents, of which 40,000 barrels was the result of armed gangs blowing up pipelines with explosives in ten separate incidents.

The spill volume became significantly greater as the company’s officials were frequently stopped by local communities from sealing the leak and starting the clean-up, according to Shell’s Nigerian subsidiary the Shell Petroleum Development Company (SPDC).

“According to our estimations, 13,000 extra barrels of oil were spilled in 2008,” SPDC said.

SPDC reported almost 90 incidents of crude oil theft last year, during which the company witnessed a 48% increase in incidents of “malicious damage” and pipeline theft.

Nigeria’s largest private-sector oil and gas company SPDC has more than 6,000km of flowlines and pipelines, and 90 oilfields in the Niger Delta.