Israeli authorities on Wednesday morning intercepted material used to manufacture explosive devices hidden inside spools of medical material at the Erez Crossing, the Shin Bet announced in a statement.

According to the statement, the material was located during the security check at the crossing in the luggage of two sisters who are residents of the Gaza Strip. The two women had been approved to enter Israel for the purpose of receiving medical treatment for cancer, which one of the two sisters suffers from. An initial Shin Bet investigation indicated that the explosives were sent by Hamas and that the group was planning to carry out terror attacks in Israel in the near future, the statement read, adding that the material was destroyed by a sapper of the Southern District police force.

“The terrorist organizations in the Gaza Strip, including Hamas, continue to exploit the humanitarian and medical assistance provided by Israel to the residents of the Gaza Strip in order to perpetrate terrorist attacks in Israel.”

This is not the first time that a Gaza resident with a special permit to visit Israel was arrested. In June of 2016 A joint Shin Bet (Israel Security Agency), Israel Police Southern District and IDF operation resulted in the arrest of 65-year-old Faiz Atar from Bet Lahia. Atar had a permit to enter Israel to conduct trade.

The suspect was taken into custody at the Tarkumia crossing between Israel and the West Bank.

The Shin Bet said the suspect hid cash in his shoes for Hamas, and smuggled tens of thousands of euros to terrorist operatives in the West Bank.

Yaakov Lappin contributed to this report.