Hamas operatives are attempting to use the messaging application WhatsApp to lure Israeli soldiers into providing sensitive information, according to a report by Ynet.

According to the report, Hamas operatives are posing as Israeli soldiers and contacting troops through the application, asking for information on troop movements and scheduled exercises.

“The IDF is aware of the enemy’s activity and is following its efforts over social media,” said the IDF in a statement. “We call on all military and civilian personnel to act carefully and responsibly.”

The statement went on to say that “we would like to point out that this year marks the anniversary of ‘Operation Heartbreaker,’ in which the IDF exposed Hamas activity against IDF soldiers on social media. The operation contributed greatly to raising the awareness and alertness of the soldiers, which is also reflected in the current situation.”

In January 2017, the IDF uncovered a Hamas effort to lure male soldiers into providing sensitive information on social media by masquerading as women.

Since then, there have been hundreds of reports of suspicious individuals attempting to make contact with Israeli soldiers.

Israel has subsequently launched two operations—“Hunter’s Network” and “Operation Heartbreaker”—to uncover and eliminate such online threats to Israel’s security.

The IDF has warned soldiers not to upload classified information to social networks, only to download applications from reputable application stores and not to enter into online relationships with people they don’t know personally.