Soldiers patrol the Christmas market in Brussels | EPA The cost of the Brussels lockdown: €51.7 million a day Business hit hardest by shutdown as police hunted Paris suspects.

Brussels paid a high price for six days on lockdown, with the city brought to a standstill as police hunted a suspected accomplice in the Paris terror attacks.

The cost of it all? An estimated €51.7 million a day.

The Free Market, a Belgian television program, calculated that businesses bore the brunt of the financial damage, an estimated €29.7 million. According to the show, which airs on the Flemish public broadcaster VRT, the cost to restaurants was €22 million.

The Belgian government raised the threat level to four — the highest level — on November 21, and lowered it to three on November 26. Bars were told to close early, and restaurants, museums, shops, schools and the entire metro system were shut for part of the week.

The cost of ramping up security could prove even more costly for Belgium. As police hunted for the fugitive Salah Abdeslam, who lived in the neighborhood of Molenbeek and is still at large, the police union demanded an additional €100 million to carry out their duties effectively across the country.

"The police is prepared, surely, to switch to higher gear in times of crisis, but we also expect from our political leaders to provide sufficient means and personnel," the union said.

The union's call for cash came shortly after Interior Affairs Minister Jan Jambon agreed with Brussels' 19 mayors to double the size of the city's six police forces.

"It's a mystery from where they'll get these additional forces," said Vincent Houssin, the police union's vice president.

A week later, Defense Minister Steven Vandeput said that the soldiers patroling the streets of Brussels, Antwerp and other cities would cost the Belgian state €17.9 million in 2015.

Belgium has been on the receiving end of international criticism for failing to tackle the terrorist threat that led to the Paris attacks. The government promised €400 million to boost its security capabilities and anti-radicalization policy.

But the federal government, business sector and tourist industry are concerned about the long-term damage to the country's reputation.

"There are a couple of things ... that have damaged our image. This comes on top of it all," said Pieter De Crem, the state secretary for foreign trade, on Sunday.