(CNN) - Two days after Islamist militants abducted an undetermined number of hostages - including Westerners - at a gas plant in a remote section of Algeria, "ongoing activity at various locations" was continuing, a British official said Friday.
It was not clear whether that activity represented "mopping up and checking" or "something more active" being carried out by Algerian forces against the abductors, the official told CNN.
Algerian forces launched their operation upon noticing the hostages being moved toward "a neighboring country," where kidnappers could use them "as a means of blackmail with criminal intent," Algerian Communications Minister Mohamed Said told state television on Thursday.
The British official said there was a "significant" number of British victims and others were unaccounted for.
This morning on "Early Start," CNN's Matthew Chance reports on the latest efforts to end the hostage situation in Algeria.
READ MORE: Algerian hostage crisis enters 3rd day with 'ongoing activity'