(Adds govt official kidnapped for ransom, paragraphs 10-11) By Tom Ashby LAGOS, Jan 26 (Reuters) - Six Chinese oil workers who went missing in an armed attack in Nigeria on Thursday are believed to have been abducted, bringing the number of hostages from that assault to nine, an oil company source said on Friday. There are now 38 foreign workers being held by different armed groups in Africa's top oil producer, where violent crime and militancy have surged in the past 12 months. Shell had originally said three Chinese staff of China National Petroleum Corp (CNPC) were abducted and another seven were missing after the raid in which one attacker was killed. "It is believed a total of nine Chinese were abducted. There was an error in the initial counting," a source at Royal Dutch Shell <RDSa.L> said. CNPC was doing a seismic study in the Sagbama area of Bayelsa state under a contract for Shell when the raid occurred. Police said the attackers also looted CNPC's field office and took away an unspecified amount of money. The Chinese embassy in Nigeria declined to comment. Militants and criminals seeking ransom have intensified attacks and kidnappings against foreign workers in the Niger Delta, a vast wetlands region which has all Nigeria's oil. Oil output from Nigeria, the world's eighth largest oil exporter, has been reduced by a fifth since a series of militant attacks last February. THOUSANDS LEAVE Outside the delta, gunmen kidnapped a state government official from her home in eastern Anambra state and demanded 50 million naira ($390,000) for her release, authorities said. Abductions for ransom are almost unheard of outside the delta and this was a sign the trend might be spreading. Thousands of foreign oil workers have left the delta in the past year and some industry executives see the region descending further into anarchy as landmark elections approach in April. Poverty and corruption fuel militancy and crime in the delta's neglected communities, where many feel cheated out of the oil wealth being pumped out of their land. Despite the rising chaos, energy-hungry China has moved aggressively into Nigeria's oil business in the past 12 months. State-owned CNPC bought drilling rights to four oil licences in May in exchange for commitments to invest $4 billion in Nigerian infrastructure. China agreed to bid for an oil refinery in northern Nigeria and build a power station. In Rivers State on Tuesday, ransom seekers kidnapped two engineers, one American and one Briton, at gunpoint from their car on the way to work. That followed the abduction of 24 Filipino seamen from a cargo ship in a remote creek in Delta State on Saturday. Those kidnappers are demanding the release of two jailed leaders from the delta, and a change in the ruling party's candidate for governor of the state in April's elections. The April elections should mark Nigeria's first fully democratic transition but many expect politicians to arm thugs to influence the polls, especially in the delta where elected office comes with a slice of oil revenue. (Additional reporting by Ijeoma Ezekwere in Anambra)
