( CNN ) -- At least two Americans , two Frenchmen and one Canadian were kidnapped early Monday by an armed group that raided an oil rig off the Nigerian coast . Two crew members are in stable condition at a shore-based clinic , where they were airlifted after being wounded in the leg . The rig off the southern coast of Nigeria at Okoro field is run by Transocean and owned by London-based Afren PLC , which detailed the hostages ' nationalities and said that five were believed to have been kidnapped . State Department spokesman P.J . Crowley put the number of hostages at seven and confirmed that two are U.S. citizens . `` We ( are ) , of course , concerned about their safety and hope for their immediate release , '' he said . `` We are working with Nigerian authorities ... to pursue their prompt release , and there 's an investigation already under way . '' Residents of Silver Creek , Mississippi , described James Robertson , one of the men kidnapped in the raid , as a `` real nice guy , '' according to CNN affiliate WLBT . `` He 's a great person , over there doing his job , '' said Larry Smith . Kacey Slocum , who used to live down the road from Robertson , told WLBT that she and others were praying for their neighbor 's safe return . She added that the nature of the raid made it all the more distressing . `` I never thought there would be pirates in 2010 , '' said Slocum , whose husband also works offshore on a rig near South America . Drilling operations in the Okoro field off Nigeria have been temporarily suspended , both companies involved said . In a news release , Afren said a `` security breach '' occurred soon after its `` High Island VII jackup rig '' arrived but before drilling had commenced . `` The situation has not been resolved . Afren is doing everything it can to resolve the situation as quickly as possible , and it is working with relevant agencies in the Nigerian government , '' Afren public relations spokesman James Henderson told CNN . The kidnappers have n't contacted Transocean , said Guy Cantwell , a spokesman for the Houston , Texas-based company . `` Clearly , the industry is on heightened alert , '' Cantwell said . `` We 're in wait-and-see mode . '' Transocean operates six offshore rigs in Nigeria -- two deepwater rigs , two ultra-deepwater rigs and two shallow water rigs , including the one involved in the incident -- according to Cantwell . The company has `` taken additional safety precautions '' on its other assets in the west African nation , he added . There has been no immediate claim of responsibility for the attack , and Nigerian officials would not comment about the incident . Several militant groups in the oil-rich Niger Delta have been battling the government for years over the distribution of the country 's oil wealth . One of the largest such groups -- the Movement for the Emancipation of the Niger Delta -- is known for its kidnappings of oil workers . CNN 's Vivian Kuo contributed to this report .
NEW : Neighbors of a hostage from Silver Creek , Mississippi , call him a `` really nice guy '' Two crew members were flown to a clinic after being shot in leg and are in stable condition . The rig attacked by an armed group is off the southern coast of Nigeria . No one has yet claimed responsibility for attack ; Nigerian officials offer no comment .