(CNN) -- Police from the Danish Security Intelligence Service have arrested eight people accused of storing "unstable explosives" in a heavily populated area of Copenhagen, agency Director Jakob Scharf said Tuesday.
Danish police work in a cordoned off street following the arrests.
Scharf told reporters in Copenhagen that the arrests overnight near Denmark's capital city had "prevented a terror act."
The arrests were made after a lengthy surveillance operation, he said. Eleven locations were searched.
"We would describe the main suspects as militant Islamists with international contacts," he said.
Those contacts include "leading members of al Qaeda," he said.
Six of the accused, all of whom are between 19 and 26 years old, are Danish citizens; the other two are foreigners living in Denmark, he said.
Two of the people are scheduled to make a closed-door appearance before a magistrate Tuesday.
"It is the intelligence services evaluation that we, with the arrests today, have prevented a terror act.
The arrests highlight that there are groups and individuals in Denmark who have the will, ability and capacity to commit terror," Scharf added.
Denmark was at the center of a controversy last year after a Danish newspaper published cartoons depicting Islam's Prophet Mohammed. Some Muslims believe it is forbidden by the Quran to show an image of the prophet.
Demonstrations erupted across the world in early 2006 after other newspapers reprinted the images months later as a matter of free speech.
However, many protesters directed their ire at Denmark, prompting the closure of several Danish embassies in predominantly Muslim countries, including Indonesia and Pakistan. E-mail to a friend