As one of our party ascended the route a small rock came down a couple of meters to the right and behind the belayer. I assumed it was from the climber until another came down 10-15 seconds later. Thinking someone must be innocently tossing rocks from the path along the cliff edge, I whistle loudly up the crag, and yelled "STOP", but to no avail. Another slightly larger rock came down, followed by one large enough to cause a fatal head injury.
By this point the belayer and I had moved in towards the cliff, and I had advised the climber to stop and clean down, which proved troublesome at the small single bolt, mid pitch.
By the time the climber was down the rocks had stopped, however as we were packing up to leave the area, one more smaller rock landed in a similar position to the others.
Two other climbers on an adjacent pitch who were preparing to leave as the rocks started said they would have a word if they saw anyone on the path above, however when we bumped in to them later, they said they had not seen anyone.
Discussing the incident on UK Climbing, this is apparently a relatively common occurrence at Blacknor, where the path runs close to the cliff edge, and patches of loose rock can be found.
Invest in helmets. We are new to the sport and still building our kit, but helmets should be a priority. They would not, of course, prevent an eye or facial injury to a belayer or spectator looking up, or other bodily injury.
Use a self-locking belay device so that in the event of an injury when on belay, there is less chance of the climber being dropped.
Request that BMC install signage on approaches to or along the top path at this and similar crags, to the effect that there is a path (and climbers) below, and not to throw rocks (or other items) over the edge.
Sport rock climbing
Falling rock, snow, ice or object
Rescue Services Involved?