Greek authorities evacuated at least 70,000 residents of Thessaloniki for the disposal of a 500lb World War Two bomb.
It is thought to be one of the largest wartime bombs to be found in urban Greece in addition to being one of the largest mass evacuations.
The bomb was discovered during road works last week and is due to be disposed of on February 12.
According to officials, the bomb is too degraded to tell if it is German or an Allied bomb.
Residents within a radius of about 1.2 miles of the bomb will be compelled to evacuate the area, security officials have said.
The operation has been described by one blog as the biggest evacuation of Greek civilians in peacetime. However, it is not possible to verify such a claim.
The military says an operation of this size and complexity is the first of its kind in a densely populated area of Greece and the disposal operation should take about eight hours – but may take as long as two days.
Image source Ekathimerini
About 1,000 police officers and 300 volunteers will be deployed ahead of the disposal operation. People in the city were warned to vacate their homes several days in advance.
The evacuation is expected to cause considerable disruption in Thessaloniki, with about 450 residents of a refugee camp due to be among thousands of others being evacuated to schools, sports halls and cultural centers.
The bomb was discovered last week near a petrol station during work to expand fuel storage tanks.
A state of emergency has been declared in the three municipalities affected by the defusion operation, Thessaloniki’s Deputy Governor Voula Patoulidou told the Associated Press.
The military say they will initially try to defuse the bomb’s detonator before taking the device in its entirety to an army firing range, where a decision will then be taken on how best to neutralize it.
Thessaloniki bus terminal will be closed down while trains will also stop operating. There is also expected to be some traffic disruption in addition to interruptions to church services.
It appears the bomb was dropped by British and US planes targeting German rail facilities on September 17, 1944.
Thousands of people have been evacuated from New Orleans as Hurricane Isaac makes its slow approach.
Hurricane Isaac will hit the Louisiana city exactly seven years after it was devastated by Hurricane Katrina, but it is a much less powerful storm.
New Orleans has closed its new floodgates in a bid to protect it from the effects of high waters brought by sustained winds of up to 80 mph (130 km/h).
Isaac killed at least 24 people in Haiti and the Dominican Republic.
It has also caused significant flooding and damage across the Caribbean and forced a day’s delay to the start of the Republican party’s congress in Tampa, Florida.
Hurricane Isaac will hit Louisiana exactly seven years after it was devastated by Hurricane Katrina, but it is a much less powerful storm
At 02:00 local time the Category One hurricane was almost stationery about 70 miles (110 km) south of New Orleans, according to the US National Hurricane Centre (NHC).
Tens of thousands of people have been told to leave their homes in low-lying areas of Louisiana and Mississippi, though a mass evacuation has not been ordered. Storm warnings are also in place in parts of Florida, Texas and Alabama.
Officials say Isaac is likely to weaken before it reaches New Orleans.
“We don’t expect a Katrina-like event, but remember there are things about a Category One storm that can kill you,” said New Orleans Mayor Mitch Landrieu.
Of particular concern are storm surges, with peaks of up to 3.7 m (12ft) forecast in parts of Mississippi and southeastern Louisiana. Rainfalls of up to 50 cm (20 inches) are forecast across wide areas, along with a high chance of isolated tornadoes along the coast.
The bowl-shaped city of New Orleans is particularly vulnerable to storms, with the centre of the city the furthest below sea-level.
But Mitch Landrieu said that the 8m-high levee gate which now protects the areas of the city that were badly flooded in 2005 had been closed since Tuesday morning.
Many residents of New Orleans have chosen to secure their homes but stay put, saying they were not too concerned by Isaac.
“I feel safe,” said Pamela Young from her home in the Lower Ninth Ward, a neighborhood devastated by Katrina.
“Everybody’s talking <<going, going>>, but the thing is, when you go, there’s no telling what will happen. The storm isn’t going to just hit here.”
“If the wind isn’t too rough, I can stay right here. If the water comes up, I can go upstairs.”
Nazareth Joseph, who works at a hotel in French Quarter and was in the city during Katrina, said he had a busy week ahead so would stay where he was.
“We made it through Katrina; we can definitely make it through this. It’s going to take a lot more to run me. I know how to survive,” he told the Associated Press news agency.
By Tuesday night, more than 58,000 homes in New Orleans were reported to have lost power. Outages have also been reported across Louisiana and Mississippi, affecting more than 200,000 homes and business.
President Barack Obama has declared an emergency in Louisiana and Mississippi, allowing federal funds to be released to local authorities.
Speaking from the White House, he warned residents along the Gulf Coast to heed warnings, including those to evacuate, saying: “Now is not the time to dismiss official warnings. You need to take this seriously.”
Shortly before Isaac reached hurricane status on Tuesday, Louisiana Governor Bobby Jindal said the emergency declaration fell short of the federal help he had asked for.