Nigeria militants attack Shell, amnesty hopes fade

"The government's insincerity is the main cause (of the amnesty offer not working)," MEND said on Saturday in a statement which accused the security forces of attacking a community near oil facilities and burning it down after residents had fled.

"(This) will be revenged and it is the oil companies that will bear the brunt," the group said.

Some security analysts expect the military to launch another major offensive against militants who do not accept the amnesty once the 60-day offer period ends in October.