"An explosion took place this morning in a house west of Gaza City," police spokesman Ayman al-Batnijiy said.
"The police launched an investigation into the cause of the explosion," he added.
The circumstances of the blast remain unclear, but police have not suggested Israel was responsible.
Worst bombing in years
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Ceasefire violations
Palestinian militants fired four rockets from Gaza into Israeli territory early Sunday, the Israeli military said, adding that its Iron Dome defense system intercepted one of the projectiles.
Israeli forces also targeted a Hamas mortar shell launch pad on Sunday after the latest rocket attacks.
The Israeli government said it was only hitting militant targets and warned civilians to stay away from certain sites.
Hamas, which controls the Gaza Strip, and the Islamic Jihad militant outfit had announced a truce agreement with Israel late Saturday. Israel, however, did not immediately confirm the ceasefire and said its military response to Gaza-based militant groups depended on the intensity of attacks on its territory.
But in an apparent acceptance of the Egypt-mediated truce, the Israeli military said Sunday it had lifted some restrictions along the Gaza border area.
Gaza rocket assaults had forced the Israeli military to shut down a popular beach along the border area. But after a relative calm on Sunday, Israeli authorities announced that residents could resume their daily routines.
How the Gaza protests against Israel escalated this year
The origin of conflicts in the region could be dated back centuries but this year has seen some key events leading to an escalation in the tension between Israel and Palestinians in Gaza.
Image: Reuters/A. Cohen
Palestinian PM Rami Hamdallah targeted
The convoy of Palestinian Prime Minister Rami Hamdallah of the West Bank-based Fatah group was targeted as he made a rare visit to Gaza on March 13. The Palestinian Authority said it held Hamas responsible, having failed to provide adequate security. Hamas claimed the attack was aimed at hurting efforts to achieve unity and reconciliation.
Image: Reuters/I. Abu Mustafa
Land Day march
Some 30,000 Palestinians took part in the first of the demonstrations on March 30, marking Land Day, named for the 1976 Arab protests against Israeli plans to expropriate land. Some demonstrators ran at the border fence and 16 were killed by Israeli troops with others injured, and some dying later.
Image: Getty Images/AFP/M. Hams
Netanyahu: 'We will hurt them'
Speaking on April 9 in the Israeli town of Sderot, near Gaza, Prime Minister Benjamin Netanyahu said: "We have one clear and simple rule and we seek to express it constantly: If someone tries to attack you — rise up and attack him. We will not allow, here on the Gaza border, them to hurt us. We will hurt them."
Image: Getty Images/AFP/G. Tibbon
Protesters injured
Palestinians ran to help a young man injured during the border protest on April 13. Stones had been thrown at border guards and the Israeli troops fired on the demonstrators. Some 45 Palestinians died and hundreds were injured between March 30 and April 27.
Image: Getty Images/AFP/M. Hams
Boy killed on April 20
Protest continued on April 20th, with some Palestinian protesters using kites to transport Molotov cocktails and firebombs over the fence. Israeli snipers killed at least four more Palestinians on April 20th, including a 15-year-old boy. The UN Middle East envoy dubbed the killing "outrageous."
Image: Getty Images/S. Khatib
May 15: US Embassy officially moved to Jerusalem from Tel-Aviv
US President Donald Trump's daugher Ivanka is part of the delegation that opened the new US Embassy in Jerusalem. The transfer of the embassy triggered a fresh wave of protests in which 62 people were killed. The deaths have considerably heightened tensions in the area.
Image: Reuters/R. Zvulun
US no longer seen as partner in Middle East negotiations
As the US celebrated its embassy move from Tel-Aviv to Jerusalem, Palestinian protests escalated. The events coincided with the 70th anniversary of the foundation of modern-day Israel, and Nakba Day, when Palestinians recall those who fled or were expelled as Israel was established.
Image: Reuters/I. Abu Mustafa
More than 60 people were killed in protests
Palestinians carried away a protester injured on May 15th after demonstrations marking the 70th anniversary of Nakba.
Image: Getty Images/AFP/S. Khatib
Palestinian youths run from tear gas
Hamas official Salah al-Bardaweel said on Palestinian television that all but 12 of the dead were members of Hamas. Mahmoud Abbas the head of the Palestine Liberation Organization is planning to pursue a war crimes complaint against Israel at the International Criminal Court.
Image: Reuters/I. Abu Mustafa
Israeli airstrikes pound Hamas military targets in Gaza
Following an increase in cross-border violence in mid-July, Israel pounded Hamas military targets in Gaza, while Palestinian militants fired more than 170 rockets and mortars into Israel. Two Palestinian boys, aged 15 and 16, were killed in Israeli airstrikes, according to Gaza's health ministry. Three Israelis were injured after a rocket landed on a residential home in the Israeli city of Sderot.
Image: picture-alliance/newscom/I. Mohamad
Israel temporarily closes its Kerem Shalom cargo crossing with the Gaza Strip
Days later, Israel blocked all fuel and gas transfers through the Kerem Shalom crossing with the Gaza Strip for six days "in light of the continued terrorist attempts of Hamas." Israel's defense ministry said essential food and medicine deliveries would still get through. The crossing had been shuttered to commercial trade a week earlier.
Image: picture-alliance/Photoshot/K. Omar
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'Hardest blow'
Israeli Prime Minister Benjamin Netanyahu warned Hamas of severe consequences for its rocket attacks on Israel.
"In consultation with the minister of defense, the chief of staff and the top security command of the state of Israel, we have decided on strong action against Hamas terrorism," Netanyahu said in a video statement on Saturday.
"The IDF [Israel Defense Forces] have struck Hamas with the hardest blow since Operation Protective Edge and we will increase the strength of our attacks as necessary," he added, referring to the 2014 war.
Israeli army spokesman Jonathan Conricus said air force sorties had struck about 40 Hamas targets including battalion headquarters, tunnels and logistical centers.
Two Palestinian boys, aged 15 and 16, were killed in Israeli airstrikes on Saturday, according to Gaza's health ministry. Witnesses said Israeli warplanes dropped four bombs on a building in Gaza City. The boys were nearby and hit by shrapnel.
Israel's Magen David Adom emergency service said it treated a 52-year-old man, a 17-year-old girl and a 20-year-old woman for their injuries after a rocket landed on a residential area in the southern Israeli city of Sderot.
