LAGOS, July 7, 2008 (AFP) - Nigerian primary and secondary schools remained paralysed Monday as an indefinite strike over pay increases by teachers entered a second week, union officials said.

'The industrial action will continue until the government heeds our demands for the implementation of the new salary package for our members,' union leader Ade Ademeso told AFP.

He said the Nigerian Union of Teachers (NUT) had sent a letter of appeal to President Umaru Yar'Adua to intervene in the crisis.

'As a former teacher himself, the president should understand that we are only asking for our rights,' he said.

The teachers launched a full-scale strike on June 30 to push the government to honour an agreement on an enhanced pay structure.

The teachers had earlier gone on a three-day strike, shutting down primary and secondary schools, but suspended the action after the government pledged to improve pay.

Teaching is among the worst paid professions in the oil rich country and the unions are demanding that the government start the new pay package immediately.

The Nigerian government said it would pay the new salary to teachers in federally-run schools, but it could not compel state and local government authorities to pay the enhanced rate in schools set up by them.

The union is however insisting that all teachers in the country should benefit from the new pay.