House Martin Chicks??

I just came across this beautiful scene today but was only armed with a digital camera, and the pictures are terrible because the low light caused a slow shutter speed and i didnt think at the time. But i'm pretty sure these are house martins, they are in an area that is swarming with house martins and if you look closley you can see the tail beginning to fork. My friend thinks the way there is 5 or 6 of them all sitting like this suggests  that they are not long fledged but i'm not sure. Can anyone tell me if i am correct about any of this? thank you