A court-martial is accusing 16 Nigerian officers and 72 rank-and-file troops of a string of charges from cowardice to refusing to fight in the country's northeastern Islamic uprising.

Thursday's mass trial comes two weeks after 12 soldiers were sentenced to death by firing squad for mutiny and attempted murder of their commanding officer.

Troops regularly have complained that they are outgunned by Boko Haram insurgents, that they are not paid in full and that they are abandoned on the battlefield without enough ammunition or food. Endemic corruption in Nigeria means millions of dollars goes missing from the budget to fight the 5-year-old Islamic uprising that has killed thousands.

President Goodluck Jonathan on Wednesday praised soldiers for their "patriotic zeal" that lately has "turned the tide" against Boko Haram.