A Nigerian militant group has released photos of an American oil worker taken hostage during a raid on a Chevron facility last week. The photos show the American, John Stapleton, next to a Croatian man and four Italians also seized during the raid. The men appear to be uninjured in the photos, which identify the men by name (pictured above). In a separate e-mail to ABCNews.com, the leader of the militant group, MEND (Movement for the Emancipation of the Niger Delta), claimed to have carried out a new wave of attacks today in the oil-rich Niger Delta region. THE BLOTTER RECOMMENDS Photos What’s Leading to Terror in the Niger Delta? Blotter American Among Kidnapped Victims in Nigeria Blotter Nigerian Terror Threat: $6 a Gallon Gasoline Click Here to Check Out Brian Ross Slideshows The e-mail stated that MEND had "destroyed three major pipelines in bayelsa state of the niger delta" and claimed the attack had caused an immediate power outage at an AGIP terminal in the territory of Brass. The attacks have not yet been confirmed by the Nigerian government. According to the e-mail, "All fighters involved in this attack have returned to base without further incident." MEND also warned that "we will continue indeffinately [sic] with attack on all pipelines, platforms and support vessels." Today’s raids by MEND are the latest in a series of attacks aimed at disrupting oil production in Nigeria, which is the fifth largest supplier of crude oil to the United States. MEND claims it is seeking a greater share of oil revenue for the Niger Delta region, which it says has been exploited by corrupt Nigerian officials in league with Western oil companies. Oil security analysts fear simultaneous attacks in Nigeria and the Middle East could drive the price of gasoline to $6 a gallon. Pictured above from left to right: John Stapleton of the United States, Ignazio Gugliotta of Italy, Alfonso Franza of Italy and Raffaele Pascariello of Italy. Kneeling: Mario Celentano of Italy and Jurica Ruic of Croatia.