A militant group in Nigeria's oil-producing Niger Delta said it kidnapped two German oil workers and four Nigerians on Wednesday to press for a series of social and economic demands. Oil services company B&B said six of its staff, two Germans and four Nigerians, were abducted while travelling by boat from Delta State to Bayelsa State, where the ethnic Ijaw militant group is based, according to Reuters. "Six of our staff including two Germans and four Nigerians were kidnapped earlier today. We haven't heard any word from them," said Thomas Horbach, B&B project manager in the oil hub of Warri. T.I.T. Manse, leader of the little-known Iduwini National Movement for Peace and Development, said the kidnappings were aimed at putting pressure on the local unit of Royal Dutch Shell . He said B&B was a Shell sub-contractor. Conflicts between foreign oil companies and Nigerian ethnic militants are common in the Niger Delta, which pumps almost all of the OPEC member's 2.3 million barrels per day. Many residents of the impoverished wetlands believe they are being cheated out of the huge riches being extracted from their tribal lands. Militant groups often demand money and services from companies, under threat of violence. --More 1810 Local Time 1510 GMT