By Ari Rabinovitch

JERUSALEM (Reuters) -The first group of Israelis freed from captivity in Gaza returned to Israel on Friday, on the first day of a planned four-day truce during which further exchanges of hostages for Palestinian detainees are due to take place.

The 13 released included four small children and their mothers as well as five elderly women. They were among around 240 people abducted by gunmen from the Islamist movement Hamas who rampaged through southern Israel on Oct. 7.

"Children, their mothers and other women. Every one of them is a world in themselves," Prime Minister Benjamin Netanyahu said in a statement. "But I stress to you, the families, and to you, citizens of Israel: We are committed to bringing back all our hostages."

As well as the Israeli hostages, 10 Thais and one Filipino, who were taken captive at the same time, were also freed under a separate agreement, Qatari mediators said.

The military said the released hostages had undergone initial medical checks inside Israel and would be taken to hospitals where they would be reunited with their families.

The rest of a group of at least 50 Israeli hostages due to be exchanged under a Qatari-brokered agreement are expected to be freed in the coming days and more hostages could be added if the truce deal is extended.

"We couldn't wait for the hours to pass," said Corinne Moshe, the daughter-in-law of released hostage 72-year-old Adina Moshe.

Her husband and his siblings were waiting at the hospital to reunite with their mother, who was captured by Hamas gunmen from Kibbutz Nir Oz, she told Israel's Kan public broadcaster.

Corinne's son Erez said he was waiting to see his grandmother.

"I miss her very, very much. I want her to be back already. I want to have dinner with her and the entire family again."

In exchange, 39 Palestinian women and minors detained by Israel were released on Friday, the first of a group of 150 who are due to be freed from Israeli detention under the agreement.

"The emotions are mixed emotions," said Shelly Shem Tov, the mother Omer Shem Tov, 21, who had attended an outdoor dance festival that was targeted in the attack, and was among those taken hostage. He was not among those released on Friday.

"I'm excited for the families who today are going to hug their loved ones. I am jealous. And I am sad. Mostly sad that Omer is still not coming home," she said in an interview with Israel's Channel 12.

Israeli leaders have sworn to free the rest of the hostages as the military pursues an invasion of Gaza launched in the wake of the Oct. 7 Hamas attack, which killed around 1,200 people, according to an Israeli tally.

The military campaign has killed around 14,000 Palestinians, according to medical authorities in Hamas-ruled Gaza and reduced much of Gaza to rubble.

(Reporting by Ari Rabinovitch; Additional reporting by Henriette Chacar; Editing by Andrew Heavens and Hugh Lawson)