Four Italians, an American and a Croat working for Chevron were kidnapped May 1. Militants said they would not demand any money, and that the hostages would be released in a month's time if Bayelsa state authorities did not offer any ransom money.
"Six technicians were to have been released today. We asked for a helicopter but were refused," a representative of the Movement for the Emancipation of the Niger Delta said.
The militants made no demands for the release of the captives and said they would release them unconditionally.
"Any offer of money will be considered an insult and will aggravate the hostages' position," they said.
Nigerian rebels, who are demanding a larger quota from the government during the distribution of revenue from oil production, often abduct oil workers and usually release them for a cash ransom.
"We will continue our struggle until we reach our goals," they said earlier this month.
