Prince Harry leads memorial tribute to fallen soldiers of Afghanistan - as four more comrades are killed in action

The 23-year-old Household Cavalry officer joined 200 servicemen and women on Edinburgh's historic Royal Mile ahead of a service at the city's St Giles' Cathedral.

But it came as news emerged of the deaths of four British troops, including the first woman soldier, in a blast east of Lashkar Gah.

Proud: Prince Harry, left, takes part in a memorial parade in Edinburgh to remember troops killed during his tour of Afghanistan

Today's event was held to pay tribute to the 24 British, Danish, American and Czech servicemen who lost their lives during the deployment of the 52 Infantry Brigade in Helmand Province from October to April.

Harry was among the 200 soldiers, sailors and airmen representing their units in the colourful parade through the centre of Edinburgh's Old Town.

The troops, led by a dozen-strong pipe band, were applauded by the hundreds of onlookers who made their way down to the cathedral from the start at Johnston Terrace.

There were shouts of "Well done" as the soldiers passed by.

Remember: Harry looking sombre

Harry wore his khaki service dress and a navy cap with a red trim.

The troops went on to join families of those killed or wounded at the memorial service, along with UK Defence Secretary Des Browne and his Danish counterpart, Soren Gade.

The latest deaths occurred at  about 3.40pm local time yesterday when the four soldiers' vehicle was caught in an explosion

Three of the troops were killed in the blast, while the fourth was pronounced dead on arrival at Camp Bastion, the Ministry of Defence said.

Respect: Harry sings during a service at Edinburgh's St Giles' Cathedral

It is understood that the woman was serving with the Army's Intelligence Corps.

Prime Minister Gordon Brown expressed his 'deepest condolences' to the families of the four soldiers.

The Prince spent 10 weeks on the frontline before being flown home in February amid fears for his safety when his deployment was reported in foreign media.

Around 7,500 soldiers were deployed under 52 Brigade command on Operation Herrick 7.

Friends: Harry chats with his comrades before the service

The Brigade, whose headquarters are at Edinburgh Castle, handed over to 16 Air Assault on April 10.

Harry's involvement was kept secret by the UK media to prevent details reaching the Taliban and endangering him and his comrades.

He was removed after news was leaked on a US website.