Belgian armed police have mounted raids across the nation arresting at least six suspects, following the prime minister announced an additional day of lockdown in the capital over fears that a Paris-style mass attack may possibly be imminent.

Armed police mounted searches in several components of the capital on Sunday evening and cordoned off regions close to the main tourist attraction, the Renaissance Grand Place around the town hall. The public broadcaster mentioned there were also raids close to Liège in the east and Charleroi, south of Brussels. Helicopters could be heard flying more than the capital. Police evacuated restaurants in the centre, blocked off roads and named on residents to stay away from windows.

Shortly prior to midnight on Sunday, the public broadcaster announced at least six arrests and stated the operations had concluded.

It does not seem that 26-year-old Salah Abdeslam, believed to have played a function in the attacks that killed 130 people in Paris nine days ago, was amongst those detained. Other raids in Molenbeek, a borough of Brussels exactly where Abdeslam lived, and in Charleroi, where one man was taken into custody. A further operation took location in Liège, 75 miles (120 km) east of Brussels.

Europe’s de facto capital faces an unprecedented security lockdown this week following Belgian authorities imposed a slew of security-initial measures to avert a “serious and imminent” terrorist attack.

Handout picture displaying Belgian-born Salah Abdeslam seen on a contact for witnesses notice released by French authorities. Photograph: Reuters

Schools, universities and kindergartens will be shut on Monday and the metro, shuttered all weekend, will remain closed, as counter-terrorist forces intensify their search for a network of Islamist militants involved in the Paris attacks.

Charles Michel, the Belgian prime minister, told a tense press conference on Sunday afternoon: “We nevertheless worry attacks right here like those that occurred in Paris, involving many folks striking simultaneously in several places,” adding that there have been “indications” that transport systems, commercial centres, purchasing streets and busy areas have been targets.

“We realise that these measures will complicate financial and skilled life … and we are performing almost everything we can to return to normality as quickly as feasible,” Michel told reporters.

He spoke after the government raised the threat level in and around Brussels to 4 – the highest level – and deployed hundreds of troops to supplement armed regional police.

European Union institutions will stay open, although with extra security checks, a spokesman mentioned. Officials are anticipated to issue fresh guidance on additional measures, a spokesman for the European commission mentioned late on Sunday.

Officials have also confirmed that nursery schools will be closed on Monday, adding to the chaos that numerous are predicting for the Belgian capital as the functioning week begins.

The minister of education, Joëlle Milquet, stated the closure of all educational institutions could be extended beyond 24 hours. “You do not mess around with the safety of young children and students … This was the only sure measure of protection which we could take,” she told local Tv networks.

Shops and restaurants remained shut for the duration of the day on Sunday in Brussels with couple of locals in the streets. Museums and cinemas had been also closed. Prospects for Britain’s Davis Cup tennis clash with Belgium on Friday going ahead appeared slim.

“We’ve never had this type of terrorist threat right here ahead of. It’s really unexpected, practically surreal,” stated Alinka Le Comte, 26, a shop assistant in the centre of the city.

Earlier in the day tourists continued to throng sights such as the city’s principal square. “It is reassuring to see the police. We are concerned but not frightened,” mentioned Emilio Bravo, who had travelled to Brussels from Alicante, Spain.

Nevertheless, the Sunday morning market at the city’s Eurostar terminal Gare du Midi – a single of the biggest outdoor markets in Europe – was named off. Busy trains from Paris were topic to further safety measures.

The Belgian interior minister, Jan Jambon, stated “several suspects” tied to the Paris attacks could be at big in the country, amid speculation that a series of cells may be preparing further strikes in the heart of the European Union. A meeting of safety agencies and senior ministers was held on Sunday afternoon to determine no matter whether the metro will be allowed to function on Monday morning when the working week starts.

Other measures could be relaxed, or stiffened, depending on inputs from counter terrorist agencies, officials mentioned. “We are clearly dealing with intelligent men and women who can adjust their targets and tactics based on what we do … So all this could take a specific time, that’s clear,” Koen Geens, the justice minister, told a nearby Tv network.

Numerous in Belgian’s Muslim neighborhood, which numbers about 600,000, worry a backlash as tensions continue.

“We are quite happy to see the searches and hear about the arrests,” said Dekhili Marouan, a 35-year-old catering worker who arrived in Belgium from Tunisia five years ago. “It’s frightening for everyone. I’m worried as well about folks here blaming all of us Muslims for this. These individuals who do this type of violence, they are not Muslims.”

Belgian officials have rejected widespread criticism of the country’s intelligence solutions and counter-terror efforts. But the news that a Belgian man suspected of undertaking reconnaissancefor the Paris attacks’ targets has been held by Turkish police has underlined the country’s function as a base for those behind the plot.

Belgium reportedly supplies far more foreign fighters to Syria than any other EU country in per capita terms. A lot of have come from Molenbeek, a run-down Brussels borough with a huge Muslim neighborhood that has extended been a concern.

Speaking to Belgian Television on Saturday evening, Carine Coquelet, the lawyer of a single of the two males detained in Brussels last week, mentioned her client admitted picking up Abdeslam in Paris shortly following the terrorist strike there and driving him back to Brussels. She mentioned that Abdesalam might have been wearing a belt of explosives under a coat.

The US embassy in Brussels advised Americans to cancel their weekend plans and keep indoors. The Foreign Workplace delivered similar tips for the higher numbers of Britons in Brussels, which is also residence to the Nato headquarters.

Geens, the justice minister, stated that the Paris attacks had shown that the profile of prospective targets had changed.

“It’s no longer synagogues or the Jewish museums or police stations, it is mass gatherings and public places.”