This weekend's capture of one of the suspects who helped plan and execute the November 13 Parisian terrorist attacks, Salah Abdeslam, may have inspired more terrorism, but no one is certain just yet.

In Brussels, Belgium, this early morning was tragically darkened with violence, The attacks were launched first at Zaventam airport and then one hour later at Maalbeek metro station.

Belgium's public broadcaster RTBF said at least one suicide bomber was behind the explosions at the airport. A U.S. official told CBS News that at least 11 people were killed and dozens injured in the blasts in the departure hall at Brussels Airport.

About an hour after the explosions at the airport, there was a blast at the Maelbeek Metro station in central Brussels, very near the U.S. Embassy and European Union headquarters. The Metro system was shut down. Emergency workers could be seen treating several injured people outside the metro station at Maelbeek.

A spokesman for the company that operates Brussels' transport system said at least 15 people died in the Maelbeek Metro attack and 55 more were wounded.

CBS News correspondent Elizabeth Palmer notes that in 2015 alone, Belgium convicted 33 people of joining or supporting ISIS -- some of them in absentia as they were believed to be in Syria. That, said Palmer, may just have been the tip of the iceberg.

Belgium's prime minister said there was no information immediately available to suggest a link between Tuesday's attacks and the arrest on Friday of Abdeslam.

However, a U.S. official told CBS News that the attacks have all the hallmarks of ISIS, and the fact that it could happen just shows how "relentless" the terrorists are in attempting to pull off attacks. The official said the attacks in Brussels exposed weaknesses in airport security as well as on subway systems worldwide.

Video and photos from Brussels Airport, which is located in Zaventem, a suburb just northeast of the capital, showed windows of the main terminal blown out with smoke rising from the shattered panes.

The attacks in Brussels quickly sent shockwaves around Europe, and the world, with the French halting trains in and out of Paris' main Gare du Norde station, and British authorities stepping up security around public transport hubs.

"Terrorists struck Brussels but it was Europe that was targeted," said French President Francois Hollande.

Here, in America, security will be stepped up in major metropolitan transport facilities.

Across the Atlanic, a U.S. law enforcement source told CBS News there was no new information or intelligence to suggest there was a credible threat to U.S. homeland, but authorities were exercising an abundance of caution.

There's been no new threats here across the Atlantic, however,

it was standard procedure to increase security and visibility of police following an attack like Brussels, so commuters in the U.S. capital should expect to see a higher level of visibility from police around the transit system.

Police in New York City were also ramping-up visibility and patrols.

The New Normal. *Sigh*