Security forces arrested 29 suspected Hamas members in the West Bank city of Nablus overnight Tuesday, including some who have been imprisoned in Israel in the past.
Among those detained were senior members of the Palestinian terror group, the army said.
The operation, carried out by the Shin Bet security service, the IDF, and the Israel Police, came amid concern that the activists were preparing to carry out attacks against Israeli targets.
The suspects were to be questioned by the Shin Bet.
The army noted an increase in Hamas activity in the West Bank and said members of the group have been acting on the instructions and funding of its leaders abroad.
On Tuesday the Shin Bet revealed it had prevented a shooting attack on IDF soldiers by a small, Jerusalem-based Hamas cell comprising two Palestinian men formerly imprisoned in Israel.
The cell planned to shoot soldiers on duty at a checkpoint just outside Jerusalem during the Purim holiday last month, the Shin Bet said in a statement.
While interrogating the suspects, Shin Bet investigators learned that the cell was much closer to carrying out an attack than security officials had originally thought, the statement said.
The agency said the arrests were made in early March, days before the holiday, which this year fell on March 15.
Tamar Pileggi contributed to this report.