A Nigerian militant group has said it destroyed an oil pipeline in the Niger Delta, the president's home region, a week before governor's elections there.

The Movement for the Emancipation of the Niger Delta (MEND) also threatened more attacks in future to "reduce Nigerian oil production to zero and drive off our land thieving oil companies."

Nigeria, already under pressure from a series of Islamic militant attacks, is Africa's most populous nation and top oil producer.

The group said in a statement that on Saturday at 1830 GMT, "fighters of the Movement for the Emancipation of the Niger Delta attacked and destroyed the Agip trunk line" in Bayelsa state in the Niger Delta.

The statement gave no details on the damage to the pipeline operated by Agip, the subsidiary of Italian oil group Eni. There was no independent confirmation of the group's claim, and no immediate reaction from Agip.

The armed group said the "relatively insignificant attack" was to indicate its presence in the oil-rich region and "a sign of things to come."

It accused President Goodluck Jonathan, who hails from the Niger Delta, of failing to "address serious issues facing the nation and its citizens" and of squandering public funds "on tribalistic sycophants and thugs calling themselves ex-militants".

More than 25,000 ex-militants from the region who surrendered their arms have been given payouts and vocational training under a government amnesty programme introduced in 2009.

The amnesty led to a significant reduction in militant attacks and an increase in output of oil, Nigeria's economic mainstay.

MEND warned of more attacks, including on companies from South Africa.

"Our silence thus far has been strategic and at the right time we will reduce Nigerian oil production to zero and drive off our land thieving oil companies," the statement warned.

"In the dark days to come, MTN, SACOIL, and other South African investments will pay a heavy price for the interference of (President) Jacob Zuma in the legitimate fight for justice in the Niger Delta by its people."

South Africa-based MTN is the leading telecom firm with the largest mobile phone subscriber base in Nigeria, while SACOIL is an oil and gas company also based in South Africa.

The MEND statement came several months after it suspended its attacks on oil installations and workers in the region.

Gubernatorial elections are scheduled in the state next Saturday.

Jonathan on Friday led his ruling People's Democratic Party at a rally in the state capital Yenagoa, where he criticised the immediate past administration.