BRUSSELS (CBSNewYork/AP) — More than two dozen suspects have been arrested in Belgium, France and Germany in continuing searches for suspected terrorists, authorities said Friday.

Thirteen people were detained in Belgium and two arrested in France in an anti-terror sweep following a firefight in which two suspected terrorists were killed, and more suspects are being sought, Belgian authorities said.

French and German authorities arrested at least 14 other people Friday suspected of links to the Islamic State group,  and a Paris train station was evacuated, with Europe on alert for new potential terrorist attacks.

On Thursday, Belgian police moved in on a suspected terrorist hideout in the eastern city of Verviers, killing two suspects and wounding and arresting a third.

As CBS2’s Jessica Schneider reported, officials said preparations were in the works for attacks on a grand scale.

Eric Van der Sypt, a Belgian federal magistrate, said Friday the terrorists were within hours of implementing a plan to kill police on the street or in their offices.

More than a dozen searches had led to the discovery of four military-style weapons including Kalashnikov assault rifles, Van der Sypt told a news conference.

“I cannot confirm that we arrested everyone in this group,” he added.

Visiting a scarred Paris on Friday, U.S. Secretary of State John Kerry met French President Francois Hollande and visited the sites of the city’s worst terrorist bloodshed in decades. Twenty people, including the three gunmen, were killed last week in attacks on a kosher supermarket and the offices of satirical newspaper Charlie Hebdo and on police.

Hollande thanked Kerry for offering France support, saying, “You’ve been victims yourself of an exceptional terrorist attack on Sept. 11. You know what it means for a country. — We must find together appropriate responses.”

Paris is at its highest terrorism alert level, and police evacuated the Gare de l’Est train station Friday after a bomb threat. The station, one of several main stations in Paris, serves cities in eastern Paris and countries to the east.

The Paris prosecutor’s office, meanwhile, said at least 12 people were arrested in anti-terrorism raids in the region, targeting people linked to one of the French gunmen, Amedy Coulibaly, who claimed ties to the Islamic State group.

In Berlin, police arrested two men Friday morning on suspicion of recruiting fighters for the Islamic State group in Syria.

Across Europe, anxiety has grown as the hunt continues for potential accomplices of the three Paris terrorists, and as authorities try to prevent attacks by the thousands of European extremists who have joined Islamic State extremists in Syria and Iraq.

Hollande said France is “waging war” against terrorism and will not back down from international military operations against Islamic extremists despite recent deadly attacks.

“It is not a war against religion, it’s a war against hate,” Hollande said in a speech to leading diplomats.

The Belgian raid on a former bakery was another palpable sign that terror had seeped deep into Europe’s heartland as security forces struck against militants some of who may be returnees from holy war in Syria.

After the gun smoke lifted, police continued with searches in Verviers and the greater Brussels area, seeking more clues in a weeks-long investigation that started well before the terrorism rampage in France last week. The Belgian operations had no apparent link to the attacks in France.

And, unlike the Paris terrorists, the suspects in Belgium were reportedly aiming at hard targets: police installations.

“They were on the verge of committing important terror attacks,” federal magistrate Eric Van der Sypt told a news conference in Brussels.

Belgian authorities had moved swiftly in the rustbelt town of Verviers Thursday to pre-empt what they called a major attack by as little as hours.

“As soon as I opened the window, you could smell the gunpowder,” said neighbor Alexandre Massaux following a minutes-long firefight with automatic weapons and Kalashnikovs that was also punctuated by explosions.

“As soon as they thought special forces were there, they opened fire,” federal magistrate Van der Sypt said.

“It shows we have to be extremely careful,” Van der Sypt said.  The Verviers suspects “were extremely well-armed men” equipped with automatic weapons, he said. Some of the individuals “were in Syria and had come back,” he added.

Authorities have previously said 300 Belgian residents have gone to fight with extremist Islamic formations in Syria; it is unclear how many have returned. Thousands of European extremists have also fought in Syria.

Belgian authorities had said earlier that they were looking into possible links between a man they arrested in the southern city of Charleroi for illegal trade in weapons and Coulibaly, who killed four people in a Paris kosher market last week.

Several other countries are also involved in the hunt for possible accomplices to Coulibaly and the other gunmen in the French attacks, brothers Cherif and Said Kouachi.

The Kouachi brothers claimed allegiance to al Qaeda in Yemen, and Coulibaly to the Islamic State group.

A senior Iraqi intelligence official told The Associated Press on Friday that Iraqi intelligence warned French intelligence about two months ago that a group linked to Khorasan in Syria was plotting an attack in Paris. The official spoke anonymously as he is not authorized to brief media. It was impossible to verify how serious or advanced the claims of a plot were.

Iraq’s prime minister also warned in September of possible attacks in New York and Paris.

In Washington, British Prime Minister David Cameron visited the White House to signal a united front against terror with President Obama.

“We will continue to do everything in our power to help France seek the justice that is needed, and that all our countries are working together seamlessly to prevent attacks and to defeat these terrorist networks,” the President said.

Across Europe some Jewish schools took drastic measures and shut down in response to the threat.

The NYPD has been on alert since the attacks in Paris and warned earlier this week of a threat against police officers and soldiers by Islamic State militants.

“We remain one of the most likely targets in the country if not the world, so we have to keep committing resources to this issue,” Police Commissioner Bill Bratton said Thursday. “For 13 years, we’ve been incident free with the exception of the ax attack on our officers and we work very hard to keep it that way.”

John Miller, the NYPD’s deputy commissioner of intelligence and counterterrorism, said the NYPD issued an advisory to police officers informing them of the message and reminding them to be “extra vigilant.”

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