As Belgium mourns and other European countries worry, new details have emerged about the attacks in Brussels that left 30 people dead and 230 wounded.
Police now believe two suicide bombers who detonated explosives in the Brussels airport were brothers suspected of having ties to the November terror attacks in Paris, a senior Belgian security source told CNN.
ISIS has claimed responsibility for the Brussels and Paris attacks — raising concerns that the terror group is gaining more traction in Europe.
Mother ripped from children
Adelma Marina Tapia Ruiz was moments away from boarding a plane to New York, where she and her family were looking forward to reuniting for Easter.
Her husband and 3-year-old twin girls had just stepped away from the boarding area at Brussels’ international airport. That’s when an explosion ripped the family apart, Peruvian state media said.
Ruiz, a Peruvian national living in Brussels, was killed in the blast, the Andina news agency reported. Her husband and daughters escaped serious injury.
The 36-year-old mother was one of at least 10 people killed in the blasts at the airport. About an hour later, 20 people were killed at a Brussels metro station.
“We were fearing terrorist attacks,” Belgian Prime Minister Charles Michel said. “And that has now happened.”
Brothers identified, manhunt underway
Police identified the two suspected suicide bombers at the Brussels airport as brothers Khalid and Brahim El Bakraoui, a senior Belgian security source told CNN.
The brothers are suspected of having ties to the November terror attacks in Paris, which left 130 people dead. Khalid El Bakraoui rented an apartment in Brussels that was raided last week, the source said.
The brothers were known to police for organized crime, but not for acts of terrorism, Belgian state broadcaster RTBF reported.
As officials try to learn more about the El Bakraoui brothers, investigators are scrambling to find a third suspect believed to be at large.
That man, shown in surveillance footage wearing a light-colored jacket and black hat, was seen pushing a luggage cart along with the other two suspects.
“The third (man) left a bomb in the airport, but it didn’t explode,” Belgian Interior Minister Jan Jambon said. “We are now looking for this guy.”
Authorities arrested one person in Anderlecht, Belgium, state broadcaster RTBF reported Wednesday. The person, who was not identified, was arrested in connection with the attacks in either Brussels or Paris, RTBF said.
A day of horror
Jef Versele was in the airport’s departure hall when bombs exploded.
“You cannot believe it; you cannot believe it,” he said. “It was so insane. Not in my backyard.”
The second blast inside the airport blew out windows and caused parts of the ceiling to fall, he added.
“People were on the floor,” Versele said, estimating he saw 50 to 60 who were thrown to the ground and didn’t seem to be able to walk.
“It’s horrible; Belgium doesn’t deserve this,” said Alphonse Lyoura, a baggage handler at the airport.
After the explosion in the subway station about an hour later, the city was virtually paralyzed, with most public transport shut down and residents terrified of more attacks.
Emerging from the chaos
A day after Brussels came to a standstill, the city began to move again Wednesday morning.
Some metro lines partially reopened. But the airport remained closed Wednesday and will still be shut down Thursday, keeping travelers in and out of Belgium stranded.
The country will officially observe three days of mourning, the prime minister announced.
And King Philippe and Queen Mathilde of Belgium will visit two hospitals Wednesday — the Erasme Hospital in Anderlecht and the military hospital Reine Astrid, the royal household said in a statement.
ISIS claims responsibility
ISIS claimed responsibility for the carnage, but authorities said it’s too soon to say for sure whether the terror group was behind the coordinated attacks.
In a message regarding the blasts Tuesday, ISIS noted that Belgium is one of the nations “participating in the international coalition against the Islamic State.”
The Prime Minister said Tuesday he had “no information” about who was responsible.
But Michael Weiss, co-author of “ISIS: Inside the Army of Terror,” said he wouldn’t be surprised if ISIS was indeed behind the bloodshed.
“I find it very hard to believe that it would be another group such as al Qaeda,” Weiss said. “Brussels, we have seen, is honeycombed with ISIS networks and sleeper agents.”
Two senior U.S. officials told CNN they believe the Belgium attack is tied to the same network as Salah Abdeslam — the Paris attacks suspect who was arrested in Belgium last Friday after four months on the run.
Spurred by Abdeslam’s arrest?
Weiss said Abdeslam’s arrest may have hastened an attack by ISIS.
Abdeslam was supposed to carry out a suicide bombing during the Paris attacks, Weiss said, but “by all accounts, he seems to have chickened out.”
After his arrest Friday, “it’s been reported that he is cooperating with Belgian authorities,” Weiss said.
“Now ISIS will have gotten wind of that fact, and if they fear that whatever human intelligence he has about the active networks in Europe will be given to European officials, they might have … accelerated any plans that they had for forthcoming terror attacks.”
‘A ticking time bomb’
Belgium has been a top concern for counterterrorism officials for years because of the large number of Belgian foreign fighters who traveled to join ISIS and other terror groups in Syria and Iraq. Many have been returning.
“The Belgians have been sitting on a ticking time bomb,” a U.S. counterterrorism official said.
And a Twitter post widely circulated by prominent ISIS backers Tuesday stated, “What will be coming is worse.”
The notion that the two suspected suicide bombers were known to authorities yet still carried out attacks shows how thinly spread intelligence authorities are, said CNN producer Tim Lister, who has reported extensively about terrorism.
“Even people like these brothers, who have criminal records, who have fired AK-47s at police, are still out there pretty much undetected,” Lister said.
“It’s estimated that just to follow one person 24-7 requires 25 officers or agents. There are just too many suspects to follow.”
But the interior minister said Belgians refuse to be defeated.
“Our police services and our investigation services are very professional people, but we are also convinced that also the terrorists .. are professionals too — and well trained and well formed,” Jambon said.
“So it’s a difficult battle against them. But I’m convinced that we will win.”
By Holly Yan, Catherine E. Shoichet and Margot Haddad
CNN’s Frederik Pleitgen reported from Brussels; Holly Yan and Catherine E. Shoichet wrote this story from Atlanta. CNN’s Nima Elbagir, Joshua Berlinger, Nick Thompson, Arthur Brice, Evan Perez, Pamela Brown and Shimon Prokupecz contributed to this report.