ABUJA ?- An email, saying it was sent by a Nigerian militant group based in the oil-producing Niger Delta, said on Wednesday it would bomb the capital Abuja on Independence Day on October 1.

The statement sent to media said it was from the Movement for the Emancipation of the Niger Delta (MEND), formerly Nigeria's main militant threat and responsible for years of attacks on the oil industry until a 2009 amnesty.

Several false threats purporting to be from MEND have been sent in the past and the group has regularly changed its email address. There have been no major MEND attacks since the amnesty and its former leader, Henry Okah, is on trial in South Africa for masterminding a bomb attack in Abuja last October 1.

"This e-mail address is Henry Okah's people who would like to be heard, especially at this time," said one security source, who doubted the threat.

The e-mail said MEND would put bombs near the capital's Eagle Square but according to the Ministry of Interior's programme for independence anniversary events, there are no events due to happen at that venue on October 1.

A radical Islamist sect, Boko Haram, based in the remote northeast has rapidly overtaken Niger Delta militants as the major security threat in Nigeria. Boko Haram took responsibility for a suicide bomb at the U.N. headquarters in Abuja last month which killed 23 people.