Lagos - The Nigerian secret police on Saturday announced the arrest of a militant who they say confessed to carrying out recent attacks on oil pipelines in the energy-rich south.The Department of State Service (DSS) said it arrested a man named Jones Abiri who uses the alias General Akotebe Darikoro.The arrest took place on Thursday in Yenagoa in southern Nigeria, amid "ongoing tactical operations to degrade the capabilities and hideouts of criminal gangs" in the country.The DSS claimed the militant confessed to attacking pipelines operated by Agip - the Nigerian subsidiary of Italy's Eni - and Anglo-Dutch oil group Shell.Several recent attacks, including assaults on pipelines operated by Shell and Agip, have been claimed by a militant group named the Niger Delta Avengers (NDA).The DSS accused Darikoro of demanding ransom money from Shell and Agip, and of threatening to bomb the presidential villa in the capital Abuja."Darikoro is also the mastermind of the recently circulated hoax of planned overthrow of President Muhammadu Buhari by the military," the DSS said.Local media was awash recently with rumours of a planned military coup against Buhari who came to power in May last year after his victory in the March 2015 presidential vote. The DSS also said a suspected militant Stephen Mamayebo known as Oscar believed to be responsible for kidnapping an expatriate worker and killing two soldiers had been arrested. Nigeria has seen a resurgence in oil unrest since the beginning of the year.The NDA has been blamed for a wave of attacks on Nigeria's oil infrastructure since the February, but it was not immediately clear if the arrested militants were linked with the group. The attacks have cut Nigeria's oil output, already hit by falling global crude prices and hammered revenue. The oil sector accounts for 90% of the nation's foreign exchange earnings and 70% of government revenue.