Police powers watchdog viewed Derry Day parade from Silver command room

He also believes the armed forces can continue to be considered a background option for the PSNI with their first port of call other police forces in Britain.

The independent reviewer of police powers and military complaints in Northern Ireland also visited Londonderry's Strand Road police station over the past year-and-a-half to view operations.

In his third annual report on powers contained in the Justice and Security (Northern Ireland) Act 2007 Robert Whalley CB also refers to the upsurge in activity by violent republicans including a significant "day of disruption" in Londonderry on March 19 last year.

In the newly published report he explains how police described to him "the extensive attempts which were made on March 19, 2010, to disrupt the public in Belfast and Londonderry."

"In particular, they have explained in some detail the sequence of events in Londonderry on that day.

"This involved four incidents: an abandoned van outside Strand Road PSNI station, the report of a van outside the courthouse, reports of a partially exploded landmine at Ballyarnett on the main road north-west from the Foyle Bridge and a bomb on the gas line on the Craigavon Bridge."

Mr Whalley concluded that these reports required an immediate and comprehensive police response to protect public safety.

"This included cordons and the specific use of powers of stop and question (section 21), entry (section 23) and the search for munitions, including vehicle searches (sections 24 and 26 and schedule 3).

"The tactical needs were complex: to preserve life (the public in general and police officers at Strand Road police station and people using the court premises in particular), to minimise disruption to the public, to preserve

forensic evidence and to maintain a 999 emergency response in case of further threats," he reported.

He said a tactical response of this kind needs to draw on police training and operational planning and requires the use of the most appropriate power to deal with the rapidly changing demands presented by the four simultaneous but differing incidents.

Elsewhere in the report Mr Whalley mentions a visit to Strand Road PSNI station where he discussed the use of stop and search powers with officers of various ranks, and examined the records kept in those stations.

His report also refers to an incident in Londonderry, when five shots were fired at police officers in the Bogside area.

Equally, the security watchdog explains how he was present in the PSNI's Silver command room to observe the police handling of the Relief of Derry celebrations in 2009. He found the conduct of the PSNI on that day praiseworthy.

"A similar strategy was followed in Londonderry on 14 August. The scale of the police operation in a closely confined area, almost every part of which is replete with historical resonance, was enormous, not least dealing with over 100 bands and feeder parades coming into the city," he wrote.

"I met some of those who had been involved from the community in the planning for the impact of the parades on the city, especially its commercial and retail activity.

"I was also aware, in the Silver command operations room, of the need at certain points for the police to take rapid operational decisions, and the extent to which they had planned in advance to keep in constant touch by mobile phone with many of the key players on the day, a strategy which required fast reaction, especially when the parades were returning.

"At the ground level, I observed police officers deal firmly but courteously with a young man whose dress and behaviour were likely to cause trouble as the parade went through the Diamond.

"The instant gathering of a group of young men watching what was happening showed the need for the utmost calm and restraint on the part of the police," he noted.

In terms of military complaints Mr Whalley said 56 were received between August 1, 2009, and July 31, 2010.

He pointed out how the post of General Officer Commanding of the Armed Forces in Northern Ireland ceased to exist in January 2009 and the role was subsumed under that of Brigadier 38 (Irish) Brigade, with whom he continued to liaise.

He said the complaints related mostly to military aviation, were dealt with effectively and that the departure of the Pumas of 230 Squadron RAF removed a major source of complaint from previous years.

Mr Whalley did, however, note that the army could be regarded as a background option if the PSNI needed their support.

The armed forces currently operate in Northern Ireland under Operation Helvetic, the successor since August 1, 2007 to Operation Banner.

He wrote: "The armed forces can continue to be regarded as a background option and any reinforcements which PSNI require can be found from police assets from forces in Great Britain, drawing on standard mutual aid arrangements. "The option of planning and training for such dispositions is a welcome assurance to the public in Northern Ireland."