Image caption Hundreds took part in the march on Anglesey

Hundreds of submariners have taken part in a march on Anglesey to celebrate Armed Forces Day.

Members of the Royal Navy Submarine Service (RNSS) received the Freedom of the County during a parade at Newry Beach, Holyhead.

The navy frigate HMS St Albans is berthed in Holyhead port and members of the public have been visiting throughout the day.

A ceremony to mark the loss of HMS Thetis 80 years ago has also been held.

Media playback is unsupported on your device Media caption Hundreds took part in the march on Anglesey

The submarine was being tested when it sank off the Welsh coast with the loss of 99 lives in June 1939.

The boat had twice the usual number of people on board, with crew supplemented by engineers from the ship builders Cammell Laird.

Seawater flooded in through a torpedo tube and the boat nosedived 12 miles off the Great Orme in Llandudno.

Image copyright Keystone-France/Getty Images Image caption Submariners commemorated the sinking of HMS Thetis off the north Wales coast in 1939

Image copyright Getty Images Image caption The Thetis was beached at Moelfre on Anglesey, before being salvaged in Holyhead

Image copyright Getty Images Image caption The Royal Navy returned to the spot in 1939 to honour those who died

Air ran out faster than usual because of the numbers on board, and carbon dioxide levels rose quickly, with only four people surviving.

The vessel was recovered and brought to Anglesey on 3 September 1939.

It was salvaged and re-commissioned as HMS Thunderbolt before being lost with all hands in 1943.

Wreaths were laid at Holyhead Maritime Museum in memory of the lost submariners.

The RNSS is also celebrating its 50th anniversary of the Continuous At Sea Deterrent.