2 sets of green lights showing for on coming and already on the roundabout traffic

As I was exiting the A19 onto the roundabout to get onto the A690, the green lights were on when I pulled out. As I pulled out I noticed 3 other cars creeping forward that were already on the roundabout. These 3 car then came forward quite fast nearly causing a collision with my car. I could not see their lights however I don't believe that 3 different cars across the 3 lanes would all jump a red light so I'm assuming theirs was also green. Roadworks have been taking place on this roundabout since October and I wonder if they are not being monitored correctly.