The whereabouts of the 14 staff of Nestoil Plc abducted in Ogba Egbema/Ndoni Local Government Area, Rivers State, remains unknown.
The workers were seized Friday morning on their way to work at a spot close to Omoku.
Gunmen hijacked the bus and diverted it to a hideout.
Rivers State Police spokesman, Omoni Nnamdi told Vanguard on Monday that efforts were still on to free the hostages.
Urging the public to support the Police with information, he said more security men had been drafted to comb suspected areas for the hostages.
He, however, said he was unaware if any demand for ransom had been made by the abductors.