Reports from Fiji say soldiers have taken a union leader, Taniela Tabu, to the army camp for questioning shortly after public sector unions announced they would go on strike tomorrow.
Fiji media report that Mr Tabu, who is the general secretary of the Viti National Union of Taukei Workers, was taken to the camp this morning.
It is not known why he was detained and when he will be released.
Mr Tabu has been among those calling for the removal of interim finance minister, Mahendra Chaudhry, saying the minister was running the government.
Mr Chaudhry, a former union leader, has been defending pay cuts and the lowering of the retirement age as part of a government initiative to cope with the economic difficulties facing Fiji.
Yesterday, the military took in for questioning a Daily Post employee after the newspaper reported that a senior interim government minister is being investigated for tax evasion.
The state of emergency was lifted at the end of May but the military has continued to take people to the barracks for questioning.
Parents of school pupils are reportedly being advised to consider keeping their children home from tomorrow when a nationwide teachers strike begins.
Members of the Fiji Teachers Association, or FTA, are among thousands of public servants expected to walk off the job after the interim government rejected their demands.
The unions have been demanding staggered restoration of a five-percent pay cut and discussion for several other grievances.
Some schools will be hit hard by the teachers strike.
The deputy principal of Cila Central school in Nausori, Bani Bolatolu, says about 54 percent of their teaching staff are with the FTA.
He admits Fiji Teachers Union members and other teachers will have to bridge the gap left by the strike.
"It has been coming in on the television and the radio... parents have been advised to think about their children, looking after them at home.. that it would be advisable. Because we cannot tell them straight not to come to school [government policy]. But otherwise the FTU and non-members will have to supervise, right."