Sky’s Ian Woods, who is on the scene, said: “There were several bursts of gunfire that lasted about 10 seconds. Since then we’ve heard four or five explosions.”
After this there was around a minute of silence, followed by further explosions.
Woods added: “Clearly this is the end game of this operation.”
Several ambulances have been seen travelling at speed in the area of the factory complex following the explosions, close to the outskirts of Paris and near to Charles De Gaulle airport.
The two terror suspects had been surrounded at the print works for several hours.
They took refuge in the building with a hostage after being forced off the road into Paris by a police roadblock.
Earlier in the day they broke cover from an area northeast of the capital and stole a car, before heading towards Paris.
A police chase took place and they were forced off the road close to the city’s outskirts.