[03:38.36]Will Ross reports from Lagos.
[03:40.43]An email statement from the militant group known as Mend, said it carried out the attack.
[03:45.52]It is, however, hard to verify if the email is from the same group responsible for disrupting oil output before an amnesty was agreed four years ago.
[03:54.07]Last week, an email purportedly from Mend said it was relaunching a campaign of violence in retaliation for the recent jailing of its leader, Henry Okah for terrorism.
[04:04.63]The Nigerian police denied there is any link between the ambush and the threat by the militants.
[04:09.96]A police spokesman said the men who opened fire were former militants involved in a dispute over amnesty payments.
[04:16.01]Tens of thousands of supporters of the Venezuelan opposition candidate Henrique Capriles
[04:22.11]have taken to the streets of the capital Caracas ahead of elections to choose a successor to the late President Hugo Chavez.
[04:29.64]Supporters of Mr Capriles said the march is an opportunity for the people of Venezuela to say the country needs a new leader to tackle its economic problems.
[04:38.76]Venezuelans go to the polls next Sunday.
[04:42.16]And finally, Scientists say airborne particles from burning fossil fuels are stunting the growth of coral reef south of the coast of Billes in Panama.
[04:51.54]The research shows that particles have a cooling effect on sea surface temperatures which limits growth.