Brussels is a city in mourning. Overwhelmed in grief, people gathered to pay tribute to those killed and wounded in Tuesday’s terrorist attacks.

CCTV’s Kate Parkinson reports.

There is a sense of shock and sadness.

In reality, the attack could have been considerably worse. The Belgian prosecutor said a third unexploded bomb was by far the biggest device and if it exploded, many more could have been killed.

Police have named two of the attackers as brothers Khalid and Ibrahim el Bakraoui. Khalid, 27, blew himself up at the Maelbeek metro station. Ibrahim, 29, seen in the middle of an image circulated by authorities, was one of the airport suicide bombers.

The man on the left of the image also blew himself up.

The third man is on the run. The Belgian media has identified him as 24 year-old Najim Laachraoui, but authorities haven’t confirmed that. It’s believed Laachraoui made the bombs used in last November’s Paris attacks.

Across Europe, there was solidarity for Belgium.

Particularly in France, which was twice the target of terror attacks last year. One of which was planned in Brussels. Tuesday’s attacks may be linked.

There is a determination in Brussels that life must go on, but there is also a sense that a pervasive threat of terrorism will be part of that life.

This was the third terror attack in Europe in 15 months. With security services seemingly powerless to prevent them, people are acutely aware of how vulnerable they are.

Belgian attacks underscore Turkey-EU agreement to secure borders

Turkish President Recep Tayyip Erdogan said Turkey had detained one of the Brussels’s attackers in June and deported him to Belgium. For years, the EU and Turkey have been working towards tightening security in the wake of terrorist threats coming from the region.

The recent terror attacks in Brussels places the spotlight on a new agreement between the EU and Turkey to rein in the flow of refugees crossing European borders.

CCTV’s Natalie Carney reports from Istanbul.

Belgian attacks underscore Turkey-EU agreement to secure borders

Turkish President Recep Tayyip Erdogan said Turkey had detained one of the Brussels's attackers in June and deported him to Belgium. For years, the EU and Turkey have been working towards tightening security in the wake of terrorist threats coming from the region. The recent terror attacks in Brussels places the spotlight on a new agreement between the EU and Turkey to rein in the flow of refugees crossing European borders. CCTV's Natalie Carney reports from Istanbul.

On Saturday, a suspected ISIL suicide bomber killed four and himself in one of Istanbul’s most popular shopping districts. Intelligence officials later learned they had foiled a attempt to conduct a “Paris style” attack across the city.

This came only days after another terrorist group killed 37 in the heart of the capital Ankara.

Despite its own domestic problems, Turkey has also been accused of serving as a transit country for terrorists.

Ankara’s “open door” policy for Syrian refugees and its porous landscape leave its borders vulnerable to the illegal crossing of potential extremists.

Ankara has been criticized for their slow response. But there have been improvements.

Since 2016, security personnel have captured close to 300 suspected ISIL militants along its border with Syria and more than 1,200 in the last 14 months, including one of the Brussels’s attackers, who was caught in Turkey last June and later deported to the Netherlands.

Erdogan said Belgian authorities could not establish any links to terrorism so they released him.

“One of Brussels attackers was caught in Gaziantep in June 2015, and deported. We reported the deportation to Belgian authorities on July 14, 2015, with a deportation notice. Despite our warning that this person was a foreign terrorist fighter, Belgium authorities couldn’t find a link to terrorism,” Erdogan said.

Turkey has also taken drastic steps to reduce the threat of potential terrorists leaving the country. Since the agreement to stem the flow of refugee and migrants between Turkey and the EU was signed on Friday, the Turkish coast guard has intercepted more than 2,000 migrants, some of which, the EU fears, could have bad intensions.

One of the suicide bombers in last year’s deadly Paris attacks was also deported back to Belgium by Turkish officials for trying to travel to Syria.

Raid at bomb-maker’s apartment reveals chilling details

As horrific as the attacks in Brussels were, they could have been a lot worse. Belgian authorities are disclosing details about the bombs that did not go off.

CCTV’s Olly Barratt reports.

When Belgian police raided an apartment in the Schaerbeek district of Brussels, they found a makeshift bomb-making factory.

Belgian police got about a tip about the location from a taxi driver who drove the attackers to Zaventem Airport.

One bomb went off. Another didn’t. The trio left behind what may have been another bomb.

At the airport, the driver told authorities he saw one of the men drop a “big bag.”

“His bag contained the most important blasting charge. Just after the arrival of the bomb disposal unit the bag exploded due to the great instability of the explosives. Thankfully no one was injured due to the professionalism of the people in charge,” Belgian Federal Prosecutor Frederic van Leeuw said.

The bomber identified as Ibrahim el Bakraoui left behind a note on a laptop recovered by police from a trash can near the Schaerbeek building.

The note said: “I don’t know what to do, being searched for everywhere, not being safe. If it drags one it could end up with me in a prison cell next to him.”

“Him” likely refers to, Salah Abdeslam, the lone surviving fugitive from the Paris attacks.

Abdeslam eluded arrest until last Friday. El Bakraoui’s note suggests Abdeslam’s capture may have accelerated the timetable for the Brussels attacks.

Now the hunt is one for the third man in the airport photo. The Belgian media identified him as Najim Laachraoui.

His undetected presence in the Muslim enclaves of this city, along with his alleged accomplices in terror, has raised unsettling questions for all of Europe about this city’s security, and the toxic radicalism in its midst.

Security analyst Scriven King on Brussels attacks

CCTV America’s Mike Walter interviewed Scriven King, a national security analyst about the Brussels terror attacks.

International diplomacy consultant Afzal Ashraf on Brussels attacks

CCTV America’s Asieh Namdar also interviewed Afzal Ashraf, a consultant fellow in international diplomacy at the think tank, the Royal United Services Institute, about the Brussels terror attacks.