Two thousand veterans of the British army’s deployment in Northern Ireland during the Troubles are expected to attend a deliberately low-key commemorative service in England to mark 50 years since troops first went on the streets.

Ben Wallace, the defence secretary, will be present at the National Arboretum in Staffordshire, but he will not make a speech.

More than 3,600 people were killed during the Troubles, including civilians, paramilitaries and 1,441 armed forces personnel, in a conflict that officially ended in 1998 but the legacy of which remains contentious.

Lt Gen James Bashall, the president of the British Legion. which organised the event, said that the ceremony intended “to honour the service and sacrifice of those from military and emergency services” who served in what is known as Operation Banner by the military.

But as many as 10,000 people are expected to attend a separate event on Saturday in Lisburn, Northern Ireland, organised by the Northern Ireland Veterans Association. All veterans and their families have been invited to attend.

Some veterans have complained that the MoD is not organising the commemoration in a year when a string of official events were held to mark the 75th anniversary of D-day and 50 years of nuclear weapons deployment was marked at Westminster Abbey.

Earlier this year, Richard Kemp, a former commander of British forces in Afghanistan, said the decision was a “deliberate snub”. Another Northern Ireland veteran, Labour MP and Sheffield city mayor Dan Jarvis, said that “we should not forget the service and sacrifice of our armed forces” and “the wider human cost of the conflict” even though the decision to deploy troops remains contentious.

About 300,000 military personnel served in Northern Ireland between 1969 and the official end of Operation Banner in 2007, making it the longest continuous deployment in modern UK military history.

Troops were first deployed on 14 August 1969 after rioting broke out in Derry, which began after nationalists threw stones and bottles at a contentious Protestant Apprentice Boys parade two days earlier.

The presence of the army was broadly welcomed at first on both sides to restore law and order, but the presence of British forces became a source of nationalist resentment and violent conflict began a year later.

Thirteen civil rights protesters were killed by paratroopers in Derry in 1972 on what became known as Bloody Sunday, although it was only earlier this year that one of the soldiers, soldier F, was prosecuted for the murder of two of the protesters. He is due to appear in court next month.

The decision to prosecute only one soldier prompted anger from nationalists, while several Tory MPs including the veterans minister, Johnny Mercer, have called for British soldiers to be included in a controversial proposed amnesty from historical prosecution.

Soldiers were repeatedly targeted by the IRA in subsequent year. The last soldier killed during the Troubles was L/Bdr Stephen Restorick, 23, who was shot dead by a sniper in February 1997.

In Northern Ireland, the anniversary is being marked with a mix of melancholy, nostalgia and recrimination, as well as anxiety over a new round of sectarian tension.

Activists who marched for equal rights for Catholics in 1969 have rued how a peaceful campaign inspired by the US civil rights movement helped light the fuse for three decades of violence that claimed so many lives.

Participants at seminars, commemorations and other events in Derry and Belfast have debated who was to blame and whether the carnage could have been avoided.

In a memoir published this week, the writer Malachi O’Doherty said Catholics started the riots that triggered a backlash from police and loyalists that in turn led to the start of Operation Banner.

“There are lessons to be learned from that week,” O’Doherty wrote in the Belfast Telegraph. “The main one is that when you live in a divided society you have to make an effort to understand the perspective of the other side. There’s no sign of much of that happening.”

The 1998 Good Friday agreement largely ended the violence but the collapse in power-sharing, tension over Brexit and a recent spate of clashes shows there is still a glow in the embers.

Youths in the nationalist Bogside area of Derry have hurled petrol bombs and paint bombs at police for three consecutive nights.

The clashes followed a march through the city by an Apprentice Boys loyalist flute band that wore the insignia of the parachute regiment – a provocative expression of support for the regiment involved in Bloody Sunday.