On Saturday, the two-year-old daughter of a boat driver was abducted by an unknown gang in the Bayelsa state three days after the Nuselba Usman, daughter of a Nigerian employee of Shell was taken hostage. Usman was released early Sunday, but the police said no ransom was paid.

In July, a 3-year-old was seized from his father's car after gunmen smashed the window. The kidnappers demanded a ransom of nearly $400,000 before releasing Samuel Amadi, the son of a prominent town chief.

That attack came just four days after a 3-year old British toddler was released after four days in captivity.

Militant attacks on Western-run oil installations since early 2006 have forced companies to scale back production and pull thousands or workers from Niger Delta, where most of the country's oil is pumped.

Nigeria's new oil minister Odein Ajumogobia has said "significant progress" has been made in addressing the issues of the Delta where chronic violence, sabotage and kidnappings are a daily occurrence.

Speaking to reporters at his first OPEC meeting in Vienna last week, he said a new Niger Delta 'master plan' had the full support of the president and would tackle the root of problems in the region of swamps and mangrove-lined creeks and home to some 20 million people from 40 ethnic groups.

Intense efforts are needed to stamp out a culture where companies are willing to pay out ransoms in the lucrative business of kidnapping children and ending what has become a cycle of revenge violence.