Investors dumped shares in European travel companies Tuesday after yet another terror attack on a major capital city.
Airline stocks were hardest hit after a suicide attack at the international airport in Brussels, the Belgian capital. Another explosion was reported on the city’s subway network.
At least 23 people have been killed, according to local media, 10 at a subway station and at least 13 at the airport.
The airport and all metro stations in the city were closed.
Airline stocks across Europe fell by between 3.5% and 4% in early trading. That includes carriers such as Air France KLM (, British Airways operator IAG and )Deutsche Lufthansa (. Airport operators in Frankfurt and Paris were trading 2% lower. )
Hotels group Accor ( was trading down 5%, while )Intercontinental Hotels ( declined 3%. )
Yet another terror strike at the heart of Europe is bound to unsettle investors. All European stock markets fell, and U.S. stock futures were trading lower.
Security was being stepped up at other major European airports, and on the transport network in New York.
“In light of the events at Brussels airport we are working with the police who are providing a high visibility presence at Heathrow,” London’s main airport said.
In New York, police said they were stepping up security in the city’s subways and other sensitive areas. Extra security was also being deployed at regional transportation hubs including Penn Station and Grand Central Station.
Brussels is the de facto capital of the European Union, and home to many of the continent’s administrative and political organizations. A senior EU official tweeted that all meetings of EU institutions have been canceled.
The attack follows a suicide bombing in central Istanbul on Saturday that killed four people, including two American-Israeli dual citizens. The attack was the latest in a string of incidents targeting civilians in Turkey.
In November, nine terrorists killed 130 people with guns and bombs in Paris restaurants, shops and a concert venue.
In the wake of the Paris attacks, French and Belgian authorities intensified efforts to identify and monitor terror suspects, including European citizens who may have returned from fighting in Syria’s civil war.
— Chris Liakos contributed to this article.