Israel is now more optimistic about a possible hostage deal in Gaza, Foreign Minister Gideon Saar said, amid reports that Hamas had asked for lists of all still held by fighter groups in the Palestinian enclave, Reuters reports.

He said indirect negotiations were under way about the return of about 100 hostages and that, while it was still too early to be sure, prospects had improved.

“We can be more optimistic than before but we are not there yet. I hope we will be there,” Saar told a press conference in Jerusalem, reiterating Israel’s position that the hostages still held in Gaza must be returned before Israel agrees an end to the fighting.

“There will not be a ceasefire in Gaza without a hostage deal,” he said.

A Palestinian official with knowledge of the mediation effort said Hamas had asked other factions in Gaza to start listing the names of Israeli and foreign hostages in their custody, whether dead or alive.

The official gave no further details of the mediation effort but said the mediators, backed by the United States, had stepped up contacts with Israel and Hamas.

Hamas officials declined immediate comment.