She specifically pointed to the fact that prior to the arrests, it was very difficult to track the scattered terrorist network and identify particular individuals who could be members of the jihadist cell.
"The fact that this has happened is a huge success but it is just the tip of the iceberg," Singh said.
She also said that the problem with international terrorism is that its diversity makes it very difficult for law enforcement to penetrate any particular terrorist network.
Separately, she underscored that the radicalization of Islam was problematic.
"There has been increasing radicalization happening on the ground within Europe", she said.
Singh added that the arrest of the 13 suspected members of the jihadist cell was a particularly important move.
"First of all, it shows a very concrete step toward cooperation between at least six EU countries", she said.
According to officials, all the detainees were members of the jihadist cell Rawti Shax. The group is known for providing financial and logistical support to terror organizations in the Middle East as well as training foreigners for a future conflict in Kurdistan.
The network was also trying to free its leader, Mullah Krekar, who is currently serving a prison term in Norway for making threats and instigating other people to commit criminal acts.
