A massive security operation on land, air and sea has begun in Greece ahead of this week's European summit outside Thessaloniki.
Police are trying to avoid a repeat of the G8 summit violence
More than 15,000 police and soldiers are being deployed to guard the Chalkidiki peninsula, where 30 European leaders will gather on Thursday in the exclusive resort of Porto Carras.
Greek police, fearing both terrorist attacks and violent street protests, have thrown up an unprecented security screen for the summit.
This is the biggest security operation that has ever been designed with the participation of all of the country's armed
Greek police spokesman
Surface-to-air missiles and naval vessels are being deployed, along with 4,000 army, navy and air force personnel.
On land, riot police will be on standby to deal with the sort of street protests which have blighted a whole series of EU and G8 summit, most recently at Evian in France.
Police snipers will take up position in vineyards and woodland surrounding the resort while frogmen join patrols at sea.
The peninsula itself is being all-but sealed off from the land, with measures including a seven-mile barbed wire fence topped with infra-red cameras.
"This is the biggest security operation that has ever been designed with the participation of all of the country's armed
forces," said Greek police spokesman Lefteris Economou.
"We must ensure that the location of the summit is completely safe for the participants.
"Any threat, not only from demonstrators, to the safety of the summit must be dealt with."
Tens of thousands of demonstrators are expected to converge on Thessaloniki before trying to reach Porto Carras, which is around 90 kilometres (55 miles) away.
"You can be certain of social disobedience," said anti-globalisation leader Petros Konstantinou. "We will have our voices heard, whether politicians like it or not."
The security situation is being further complicated by an ongoing series of skirmishes between Greek and Turkish military aircraft.
Greece has accused Turkey of an "astronomical" rise in its air space violations over the Aegean Sea, where the two countries do not agree over their air space boundaries.
The most serious reported incident came last week when a civilian Olympic Airways flight had to take evasive action as fighter jets from both sides squared up to each other.
As well as policing the summit, Greece is also aware that its security capabilities will be under particular scrutiny because of next year's Olympic Games.
The government has faced stinging criticism over its preparations for the games, and is thought to be determined to boost public confidence with a successful six-month spell at the helm of the European presidency and a secure summit.
Police sources have confirmed that the summit is providing useful ground as preparation for the games.
"What we learn we'll apply to the Olympics," one senior officer told Reuters news agency.
I don't trust what the politicians say. If the rally turns sour, they (protesters) will destroy my place
Meanwhile in an attempt to encourage peaceful protest, the summit organisers have laid on campsites, venues and free transport in Thessaloniki.
"We are an open, multicultural city and will welcome
demonstrators," said Northern Greece minister Giorgos Paschalidis.
But many local businesses were preparing for the worst.
"I don't trust what the politicians say. If the rally turns sour, they (protesters) will destroy my place and no one will be
able to stop this," said restaurant owner Giorgos Michailidis.
The Greek strategy appears to be to hope for the best while preparing for the worst: 33 public prosecutors have been placed on standby, in case they are needed to process criminal cases.