Police protection of landmark sites across Belfast has been tightened in advance of the G8 conference in Northern Ireland.
Some of the properties including the Parliament Buildings at Stormont will have round the clock guards.
Thousands of PSNI officers backed up by 3,600 specially trained public order police from England and Wales will be patrolling the streets to deter hard-line anti capitalist anarchists and dissident republicans from launching an attack.
“We are protecting the iconic sites from those extreme anarchist elements who may come to Belfast to try to seek to de-stabilise the G8 event and the same time protect iconic sites from any dissident republicans,” said PSNI Superintendent Alan McCrum, who is in charge of the Belfast policing operation.
Banks, building societies and key business like the Waterfront Hall, the £90 million Titanic centre and political hubs such as Belfast City Hall will also have increased security.
The threat from dissident republican terrorists who have been waging a campaign of violence against the security forces in Northern Ireland was reclassified by the Home Office as severe. It is feared some elements may seize the opportunity presented by the G8 to gain global publicity.
“Clearly because there is an increased number of police officers deployed across the city this week that heightens our concerns,” added Mr McCrum.
The leaders of the world’s eight wealthiest countries including Russian president Vladimir Putin and German chancellor Angela Merkel are due to meet at the luxury Lough Erne resort in Co Fermanagh for the two-day conference next week.
US president Barack Obama is to visit parts of Belfast ahead of the summit.
Estimates for the numbers of protesters in Belfast have been revised from 40,000 to around 10,000.
Police have also played down the likelihood of violence and said they have adopted a relaxed attitude towards a rally by the Irish Congress for Trade Unions (ICTU) and family day organised by the IF (Enough Food For Everyone) Campaign in Belfast on Saturday.
Mr McCrum said: “At this point in time there is nothing to suggest to us there is going to be any particular difficulties or challenges in the city.
“We are content to facilitate lawful, peaceful protest but we will deal with any individuals or groups who would seek to infiltrate lawful protest to damage property or create public disorder.”
Shops and restaurants in Belfast city centre have been advised not to board up windows but to take sensible precautions.
Belfast’s new Lord Mayor Mairtin O Muilleoir said: “Our message is that Belfast is very much open for business but clearly there are contingency plans in place to deal with any situations that may arise.”
Dr Anne Wilson, from the Public Health Agency who has been leading on the health operational planning for the G8 said it would be “business as usual”.
Meanwhile, Amnesty International has called for the PSNI to ensure that security and policing arrangements respect the freedom of expression and of peaceful assembly of G8 demonstrators.
“We recognise that special security measures may be necessary for such a high-profile event. However, the authorities must ensure that security arrangements do not leave the public without an effective opportunity to engage with the G8 leaders - and via international media coverage, the world - through peaceful debate, discussion and demonstrations about pressing global issues.
“We look to ministers and the PSNI chief constable to offer those assurances and to make them real through practical measures,” said Patrick Corrigan, Northern Ireland programme director.