Three sons and four grandchildren of the political leader of the Palestinian militant organization Hamas, Ismail Haniyeh, were killed in an Israeli attack in the Gaza Strip on Wednesday, Hamas sources in Beirut confirmed.

Ismail Haniyeh, chairman of the politburo of the Palestinian Hamas movement, meets with President of Iran Ebrahim Raisi (Not Pictured). Three sons and three grandchildren of the political leader of the Palestinian militant organization Hamas, Ismail Haniyeh, were killed in an Israeli attack in the Gaza Strip on Wednesday, Hamas sources in Beirut confirmed.

According to a report by the Shihab news agency, they were hit in a vehicle in the al-Shati refugee camp in the northern part of the coastal strip.

Haniyeh was quoted on a Hamas Telegram channel as saying he was "honoured" by what he termed "the martyrdom of [his] three children and some grandchildren."

"I thank God for this honour," he also said.

The Israeli army confirmed later Wednesday the targeted killing of three of Haniyeh's sons.

Three Hamas military wing operatives had been "eliminated" in the central Gaza Strip, the Israel Defense Forces (IDF) said in a statement.

The army confirmed that these were Haniyeh's sons. However, there was no confirmation of the deaths of four grandchildren in the incident.

"The IDF is aware of claims that other relatives of Haniyeh were harmed, among them a minor. This information is not verified by the IDF," the statement read.

Haniyeh reacted defiantly. The Hamas leader said the attack on his family is evidence of Israel’s "failure," Qatari broadcaster Al-Jazeera reported, adding that it will not change the group’s position in ongoing indirect ceasefire talks.

He stressed that Hamas would not withdraw its demands. "If they think that targeting my children at the peak of these talks before the movement’s response is submitted will cause Hamas to change its positions, they are delusional," Haniyeh said, referring to Israel.

Meanwhile the Wall Street Journal reported that a compromise proposal put forward by the US in indirect negotiations for a ceasefire in the Gaza war has been largely rejected by Hamas.

The militant Palestinian organization is planning to submit its own counterproposal instead, the Wall Street Journal reported on Wednesday, citing unnamed "intermediaries."

Meanwhile Hamas sources told dpa the indirect negotiations between Israel and the Palestinian movement regarding a ceasefire in the Gaza war are "not going well."

"The Israelis are not interested in a ceasefire. They are only interested in the hostage issue and not in a ceasefire," the sources said.

There is no official information on the current status of negotiations from either side in the conflict.

After talks in Cairo, Hamas representatives left the Egyptian capital on Monday for consultations with their leadership.

Since Israel and Hamas do not speak to each other directly, the United States, Qatar and Egypt are acting as mediators.

In Washington, US President Joe Biden urged Israeli Prime Minister Benjamin Netanjahu to keep his vow to improve the humanitarian situation in the Gaza Strip.

At a joint press conference with visiting Japanese Prime Minishter Fumio Kishida, he underscored "the urgent need to significantly increase deliveries of life-saving humanitarian assistance throughout Gaza."

Haniyeh, chairman of Hamas' politburo, has been living in Qatar with part of his family for years.

According to media reports the Hamas leader, who comes from a modest background, is said to be extremely rich and lead a life of luxury in Qatar.

In the attack by Hamas and other Palestinian militants on the Israeli border area on October 7, which triggered the Gaza war, more than 1,200 people were killed and over 250 people were abducted to the Gaza Strip.

Israel subsequently said it wanted the targeted killing of the Hamas leadership.

According to the Hamas Ministry of the Interior, several of Haniyeh's relatives had already been killed in an Israeli attack in the Gaza Strip in October.