As cease-fire talks are set to begin again in Cairo this week, Hamas said it fears Israel will put up more "obstacles" that could prevent them from reaching an agreement with Israel.

In a statement Sunday, Hamas leaders accused Israeli Prime Minister Benjamin Netanyahu of putting "more conditions and obstacles in the way of reaching an agreement, in a way that serves his strategy to gain time and prolong the aggression."

"We hold Netanyahu fully responsible for thwarting the mediators' efforts, obstructing reaching an agreement, and fully responsible for the lives of his prisoners who are exposed to the same danger that our people are exposed to, as a result of his continued aggression and systematic targeting of all aspects of life in the Gaza Strip," Hamas said in the statement.

One person was killed in a bomb explosion in Tel Aviv, Israel, Sunday night, according to Israeli police.

The blast occurred around 8 p.m. local time on Lahi Street in southern Tel Aviv, police said.

It was not immediately clear who or what set off the explosive.

A second person received moderate injuries in the incident and was being treated in a hospital, police said.

The name of the person killed was not immediately released.

Police forces from the Ayalon Region and the Tel Aviv District quickly arrived at the scene and launched an investigation.

All investigative avenues are being explored, police said.

-ABC News' Will Gretsky

Secretary of State Antony Blinken arrived in Israel on Sunday evening local time ahead of cease-fire talks that are scheduled to resume in Egypt this week.

Following discussions in Doha, Qatar, last week, senior officials are due to meet again this week in Egypt. Israel has said it will send a team to Cairo to continue talks, but Hamas has dismissed any hint of progress as an "illusion."

While in Israel, Blinken is scheduled to meet with Israeli Prime Minister Benjamin Netanyahu and other senior officials to press for a cease-fire agreement. Netanyahu has expressed "cautious optimism" about the talks, but said Sunday that "there are things we can't be flexible about."

-ABC News' Joe Simonetti

Israeli Prime Minister Benjamin Netanyahu said Sunday that Israel "can’t be flexible” about certain things while cease-fire talks continue.

Netanyahu commented on the cease-fire talks during his weekly cabinet meeting and ahead of Secretary of State Antony Blinken's scheduled arrival in Israel on Sunday evening local time.

"We are conducting very complex negotiations when on the other side is a murderous, uninhibited and recalcitrant terrorist organization," Netanyahu said, referring to Hamas. "But I want to emphasize -- we are conducting negotiations, not negotiation. There are things we can be flexible about, and there are things we can't be flexible about -- and we insist on them. We know very well how to differentiate between the two."

Following discussions in Doha, Qatar, this week, senior officials are due to meet again next week in Egypt. Israel has said it will send a team to Cairo to continue talks, but Hamas has dismissed any hint of progress as an illusion.

"Therefore, besides the great efforts we are making to return our abductees, we stand firm on the principles we have established, which are essential for Israel's security. These principles -- I repeat -- are consistent with the May 27 outline, which received American support," Netanyahu said Sunday.

Netanyahu said Hamas has refused to negotiate, noting it did not send a representative to the talks in Doha.

"Therefore, the pressure should be directed at Hamas and Sinwar, and not at the Israeli government," he said, referring to Yahya Sinwar, the newly named political leader of Hamas and one of the key architects of Hamas' Oct. 7 surprise attack on Israel. "The strong military pressure, and the strong political pressure, this is the way to achieve the release of our abductees."

-ABC News' Jordana Miller

Three children have presented with suspected acute flaccid paralysis, a common symptom of polio, weeks after poliovirus was detected in environmental samples from Khan Younis and Deir al-Balah.

International aid groups are calling for temporary humanitarian pauses in order to launch polio vaccination campaigns across the Gaza Strip at the end of August and September to prevent the spread of the circulating variant type 2 poliovirus.

"During each round of the campaign, the Palestinian Ministry of Health (MoH), in collaboration with the World Health Organization (WHO), the United Nations Children’s Fund (UNICEF), the United Nations Relief and Works Agency for Palestine Refugees (UNRWA) and partners, will provide two drops of novel oral polio vaccine type 2 (nOPV2) to more than 640 000 children under ten years of age," the WHO and UNICEF said in a statement.

Hamas said it supports a humanitarian pause in order to vaccinate thousands of children against quadriplegia.

"At least 95% vaccination coverage during each round of the campaign is needed to prevent the spread of polio and reduce the risk of its re-emergence, given the severely disrupted health, water and sanitation systems in the Gaza Strip," the aid groups said.