People whose family members have been taken hostage by the Palestinian Islamist group Hamas have asked the Israeli government to do all it can to secure the release of their loved ones.

About 10 family groups met with Israeli President Isaac Herzog in Jerusalem on Tuesday. They demanded information on the hostages.

One woman said her 29-year-old brother-in-law was attending a music festival that came under attack by Hamas. She said her husband's brother has been missing since Saturday.

Jasmin Oren said nearly five days have passed without any information and that her family members were starting to lose their sanity.

Oren said they are hoping for the safe return of their brother and for the Israeli government to do something.

She noted that the government may not be able to state the hostages are a top priority because it would give Hamas the message that it is open to negotiation.

But she said she hopes the Israeli government is at least developing a strategy to rescue the hostages. She suggested that Israel could consider negotiating a swap between them and members of Hamas.

Hamas has taken more than 100 people hostage, including foreigners. The militant group has threatened to execute them if Israel attacks Gaza residents without warning.