A senior Hamas official told Reuters on Tuesday that Israel is unilaterally ending the Gaza ceasefire agreement.
"Netanyahu and his government have decided to overturn the ceasefire agreement," Hamas said.
The terror organization added that this left the remaining hostages "to an unknown fate," Axios reported.
"We hold the criminal Netanyahu and the Zionist enemy fully responsible for the consequences of the treacherous aggression on Gaza," the terror organization wrote in a statement on Telegram.
In a later statement, Hamas Spokesperson Abdul Latif Al-Qanou said that Hamas had "adhered to all the terms of the agreement and was keen to move to the second phase" but Israel refused.
"Netanyahu reversed the agreement and decided to resume the war on Gaza to exacerbate his internal crisis and impose new negotiating conditions."
The Prime Minister's Office said that the strikes were in response to Hamas's refusal to release the hostages still held in Gaza.
"Israel will, from now on, act against Hamas with increasing military strength," it added.
"Tonight, we resumed fighting in Gaza due to Hamas’s refusal to release the hostages and its threats against IDF soldiers and Israeli communities," Defense Minister Israel Katz wrote in a statement.
He then threatened that if Hamas did not release more hostages, the IDF would attack more ferociously than before and unleash "the gates of hell in Gaza."
IDF is prepared, ready to attack
Senior IDF officials told Reuters that the offensive in Gaza will continue as long as necessary and will expand beyond airstrikes. They added that the IDF is prepared and spread out in all arenas.
Military officials also reported that the strikes targeted mid-ranking Hamas commanders and leadership officials and additional terrorist infrastructure. Qatari-owned broadcaster Al Jazeera reported that at least 86 people were killed.
An unnamed Israeli military official told Axios that the strikes were planned because Hamas was prepared to carry out new attacks against Israel.
The official also said the IDF kept the operation top secret in order to surprise Hamas, Axios reported.