• What happened?

Two explosions, at least one caused by a suicide bomber, in the departure hall at Brussels Airport killed some 10 people just before 8 a.m. local time on Tuesday, or 3 a.m. Eastern time.

About an hour later, an explosion at the Maelbeek subway station in central Brussels, not far from the European Union’s core institutions, killed about 20 people.

More than 230 others were wounded.

• Was the Islamic State behind it?

Eight hours after the explosions, a news agency affiliated with the Islamic State issued a bulletin claiming responsibility, calling Belgium “a country participating in the coalition against the Islamic State.”

Officials noted the timing of the attacks on Tuesday, just days after the arrest of the main surviving suspect in the assaults in and around Paris last year that killed 130 people.

“We were fearing terrorist attacks, and that has now happened,” said the prime minister of Belgium, Charles Michel.