Israeli airstrikes on the Gaza strip killed a senior Islamic Jihad commander, along with at least nine others including a five-year-old girl, prompting vows of retaliation from the militant group.
Tayseer al-Jabari, a commander of the Al-Quds Brigade - the military arm of the Islamic Jihad - who the Israeli military described as the main coordinator between Islamic Jihad and Hamas, was confirmed dead.
Following the attack, sirens have sounded in parts of Israel as rockets were fired into the country, seemingly following up on threats from the militant group.
Alongside the commander, six others including a five year-old girl died in the strikes on the centre of Gaza, the Gaza health ministry confirmed, with 44 people being wounded.
Images streamed on television showed smoke pouring from the roof of a building in the heavily populated strip, as civil defence teams rushed to the scene to evacuate the building and put out fires.
Israel said its strikes were aimed against a "concrete threat". In a statement their military said: "The IDF (Israel Defence Forces) is currently striking in the Gaza Strip. A special situation has been declared on the Israeli home front,".
Israeli attacks came amid a sustained period of tension that followed the arrest of a Palestinian militant leader, Bassam al-Saadi, in the occupied West Bank city of Jenin.
Following the arrest, the borders around Gaza were shut in the face of threats of retaliation. The closures included the Karam Abu Salem commercial crossing which is responsible for the flow of fuel for Gaza’s only power plant.
But a spokesperson for Israel said fuel trucks would be allowed across to keep the plant operational.
This evening, Israeli authorities issued a warning of rocket strikes against their cities in retaliation and said sirens had already sounded in central and southern areas, following apparent attacks.
In response to the attacks, one Islamic Jihad leader vowed there were "no red lines" in the battle as they promised Tel Aviv would fall - prompting fears the conflict could escalate into war.
Speaking to Al Mayadeen television Islamic Jihad leader Ziad al-Nakhala said: "There are no red lines in this battle and Tel Aviv will fall under the rockets of resistance, as well as all Israeli cities".
In a statement, the Islamic Jihad also promised an escalation of violence against Israel, raising further concerns of a possible war.
They said: “The enemy has begun a war targeting our people, and we all have the duty to defend ourselves and our people, and not allow the enemy to get away with its actions which are aimed at undermining the resistance and national steadfastness.”
The Islamic Jihad are a cluster of Palestinian militant groups founded in Gaza in the 1980s that opposes any political dialogue with Israel. Whilst separate to Hamas, they generally cooperate closely with the fundamentalist militant movement.
A spokesperson for the Israeli military said that authorities expected retaliation rocket attacks against Israel in the coming days but that the Iron Dome, an anti-missile system, was operational.
They added that special measures had been imposed in Israel in places within 80km of the Gaza border.
One witness to the attack told Al Jazeera: “We’ve just had Friday lunch and my children were playing. Suddenly a huge explosion hit the tower in which we live. We ran away. The sound was massive. We were very shocked as the place is full of civilians. I saw many casualties that were evacuated."
Multiple blasts could be heard and seen throughout Gaza during the attack and Israeli reconnaissance drones were reportedly seen overhead afterwards.
Fawzi Barhoum, a spokesperson for Hamas, said it would respond to Israel’s “escalation”. He said: “The Israeli enemy is the one who started the escalation against the resistance in Gaza, and a new crime was committed, and it bears the full responsibility.
“The resistance will defend our people in the Gaza Strip with everything it has and will continue to respond.”