Devonport naval base in Plymouth has been the target of anti-nuclear protests for many years.

It is the home of refitting and refuelling for the UK's fleet of nuclear-powered submarines - including the Vanguard class.

The 16,000-tonne subs, which form the backbone of the nation's nuclear deterrent, are berthed in specially-converted 9 dock because they are too big for the other docks.

HMS Vanguard arrived in Plymouth in February for a two-year refit. It is the first of four nuclear submarines due for a refit at Devonport over the next eight years.

Devonport

1980: Purpose-built nuclear submarine refit complex opened 330 acres 11 dry docks Base for seven nuclear-powered submarines

Each submarine carries 16 Trident missiles, although the missiles will not be on board while at Devonport.

The latest protests were also aimed at highlighting the issue of storing decommissioned nuclear subs at Devonport.

Eleven disused nuclear subs are stored afloat at Rosyth in Scotland and Devonport dockyards with their nuclear reactors intact, but emptied of fuel which is taken for storage at Sellafield, Cumbria.

There is no further capacity at Rosyth, but Devonport, which has four subs, is scheduled to receive a further three, when it will also be full.

The dockyard says that storing the subs is safe. It adds that it is vital to the local economy as a major employer.

Opponents say that its value is overblown and the base should be converted for civilian use.

Consultation is still going ahead, but a decision is due next year.