An Israeli advocacy group is reporting a sharp jump in the number of Palestinians from the Gaza Strip who have been summoned for questioning by Israeli security agents as a condition for leaving the blockaded territory.

Gisha, which pushes for freedom of movement for Gaza's 1.8 million people, says more than 1,200 Gazans underwent interrogations during the first half of this year. That is two and a half times the number the previous year.

Critics say the policy puts Gazan travelers in a difficult position by making them look like potential collaborators.

Israeli officials say the practice is a necessary security measure. They say that Hamas often tries to take advantage of civilians, including medical patients, in order to build up its capabilities in Israel and the West Bank.