2 March 2012
* MEND has resurfaced since pipeline attack last month
* President Goodluck Jonathan
's security forces stretched
* Local politics often fuels conflict in oil-rich delta (Adds details, background, quotes)
YENAGOA, Nigeria, March 2 (Reuters) - A Nigerian militant group based in the oil-producing Niger Delta claimed an attack on a police checkpoint on Thursday that killed four people, its second such claim after it said it blew up an oil pipeline last month in Africa
's top crude producer.
Militant activity in the Niger Delta, whose coastal areas pumps out most of
Nigeria 's more than 2 million barrels a day, has slowed to a trickle since the amnesty.
It is seen as more of a criminal enterprise making huge sums for oil thieves and pirates rather than a determined political movement.
Under the amnesty thousands of militants gave up their weapons, joined training schemes and drew stipends. Security sources say remaining gangs in the Niger Delta do not have the capacity to do the damage seen in the past.
But a resurgence of militant activity is an unwelcome headache President Goodluck Jonathan
's administration, whose security forces are already stretched by an Islamist insurgency raging in the north.