Israel’s Mossad intelligence service is hosting its Qatari counterparts to confer on the recovery of hostages held by Hamas and other elements of a Gaza truce that was mediated by Doha, an Israeli security official said on Sunday.

Qatari intelligence officers arrived on Saturday for an indefinite stay in Israel, the official said, adding that cooperation between the agencies is “traditionally close”, despite the lack of formal relations between the countries.

Qatar’s international media office did not immediately respond to a request for comment.

A Qatari delegation travelled to Israel on Saturday to discuss a possible extension to the truce, another official briefed on the visit told Reuters on Saturday, but it was unclear if intelligence officials were involved in the talks.

Gas-rich Gulf state Qatar hosts several top Hamas officials and the group’s political office. Qatar also has cordial relations with Iran, Israel’s arch-foe, which backs Hamas.