Three explosions, two at the city's airport, rocked the city of Brussels on Tuesday. The airport and all the metro stations in the city were locked down following two explosions in departure hall of the Zaventem airport and one at Maelbeeck metro station, which is close to multiple EU institutions. The multiple blasts come days after the arrest of Saleh Abdeslam in Brussels on Friday. Abdeslam was the prime suspect in the Paris terror attacks that killed 130 people in November. Two days ago, Belgium's foreign minister Didier Reynders said at the Brussels Forum on Sunday that Abdeslam has told investigators he had been planning to target Brussels.

"...he was ready to restart something in Brussels, and it may be the reality because we have found a lot of weapons, heavy weapons, in the first investigations and we have found a new network around him in Brussels," Reynders said in a statement.

In view of the advance warning given to the authorities by detained Paris terror attack suspect Salah Abdeslam, the planned terror strikes haven't come as a surprise.

Belgium- the hub of terror in the EU?

Despite the raids in Verviers in January that prevented a terrorist attack, Belgium has been strongly criticised for being poorly equipped and unprepared to counter acts of terrorism.

Terrorist links to Belgium made news recently. In recent times Belgium has emerged as a suspected hub for terror, with a large number of youngsters being recruited by terrorist organisations such as Islamic State. Here's why:

Belgium's strategic location between France, Germany and the UK is an advantage for terror groups. One can easily travel between these places and the time taken to travel between the nations isn't much.

Belgium is part of the Schengen area and its outside borders are open, making the country easily accessible.

More than 25% of the population in Molenbeek, the district which in the recent past has seen a lot of terror links, is unemployed. Due to financial troubles young minds are seem as being more vulnerable and it's easy for radicals to draw them into extremist activities.

Reports suggest that those from Muslim backgrounds face racism, which is seen making them more prone to radicalisation. According to recent estimates by International Centre for the Study of Radicalization in London, relative to the size of its population, no other country in Europe sends as many young jihadists to Syria as Belgium does.

The inability to integrate migrants, including Muslims who comprise of 6% of the Belgian population has been seen as a factor in alienating them.

A long-standing bitter rivalry between a Dutch-speaking north and a French-speaking south hasn't helped.

It's not so difficult to buy arms and ammunitions in Brussels.