Diplomatic sources said Hamas has sent scores of operatives to Turkey since 2012. They said they included senior commanders responsible for operations in the West Bank.

“Most of the Hamas people stay for a short while and then leave,” a diplomat said. “But there is a growing number of those who are permanently based in Turkey.”

Ankara, with the second largest army in NATO, has acknowledged a Hamas presence and said it would welcome additional operatives. On Jan. 7, Turkish Foreign Minister Mevlut Cavusoglu said Hamas Executive Council chief Khaled Masha’al, asked to leave Qatar, could relocate to Turkey.

“Regardless of which country they belong to people are free to come and go to Turkey as they wish, as long as there are no legal impediments,” Cavusoglu said.

The sources said the Hamas presence in Turkey was led by two commanders. They cited Salah Arouri, deemed the commander of Hamas in the West Bank and said to plan attacks against Israel. The other commander was identified as Imad Al Alami, believed to be Iran’s liaison with Hamas.

A leading U.S. analyst said the Hamas presence in Turkey, which included at least two financiers and a dozen mid-level operatives, could prepare for the arrival of Masha’al and other leaders. Jonathan Schanzer, vice president for research at the Foundation For Defense of Democracies, said Hamas would choose Turkey should the movement be expelled from Qatar.

“Turkey is right now a stronger location than even Qatar for Hamas headquarters,” Schanzer told the U.S. newspaper Algemeiner. “Masha’al’s arrival would cement the notion that Turkey is the top headquarters for Hamas.”

Israel has asserted that Qatar expelled Masha’al, who has visited Turkey several times. The Israeli Foreign Ministry raised the prospect that the Hamas leader would resettle in Turkey.

“We expect the Turkish government to act responsibly in a similar way [as Qatar],” the Israeli ministry said.