Officers of the Nigeria police force are currently stationed at the National Health Insurance Scheme (NHIS) head office in Jabi, Abuja.
The police officers arrived in the premises on Monday morning following rumours of a planned protest by the staff of the agency.
The armed officers are occupying the premises and also stationed along the road in the area.
Last week, the workers protested the reinstatement of Usman Yusuf, executive secretary of the National Health Insurance Scheme (NHIS).
Some of them vowed not to resume until his reinstatement is reversed. But on Monday, a group of workers loyal to Yusuf staged a counter-protest.
Yusuf was recalled after he was suspended last year over allegations of fraud levelled against him.
Newsmen who is currently at the agency learnt that some persons believed to be in support of the recently reinstated Executive Secretary of the NHIS boss, Prof. Usman Yusuf, are expected to hold a solidarity rally at the agency.
Yusuf, who is accused of perpetrating fraud to the tune of N919m, was controversially reinstated by President Muhammadu Buhari last week.
Unionists at the NHIS have therefore grounded activities at the agency.
Speaking at the agency on Monday, the Chairman of the Association of Senior Civil Servants of Nigeria at the NHIS, Razaq Omomeji, told members not to be intimidated.
Omomeji said the persons coming to protest were hired by Yusuf.