Following the assassination of Saleh al-Arouri in an apparent Israeli drone strike in Beirut, Lebanon, Tuesday evening, Hamas has promised revenge, saying "all options are open."

Hamas leader Ismail Haniyeh said, "This is an act of terror, the occupation will bear responsibility for the consequences of the assassination."

A movement whose leaders and founders fall as martyrs for the dignity of our people and our nation will never be defeated," Haniyeh said. Haniyeh is considered another prime target for Israel.

In the Palestinian Territories of the West Bank, a general strike was proclaimed in protest of Arouri's killing. All schools and public institutions were said to be closed in mourning of Arouri's death, and many shops were expected to remain closed as well.

In response to the assassination, Hamas spokesman Izzat al-Rishq said that "the cowardly assassinations carried out by the Zionist occupation against the leaders and symbols of our Palestinian people inside and outside Palestine will not succeed in breaking the will and steadfastness of our people or undermine the continuation of its courageous resistance."

There were large protests calling for revenge in Ramallah, Arouri's hometown, Tuesday night, after the killing was announced.

Five other Hamas members were also killed in the strike in Beirut.

Both Hezbollah and Iran have also promised revenge for the killing of Arouri. Arouri was a key figure in talks between Hamas, Hezbollah, and Iran, traveling to Tehran to meet with key Iranian leaders several times.

Lebanese newspaper Al-Akhbar, which is affiliated with Hezbollah, ran a cover story about Arouri. In the article, the newspaper said, "Hours before Hezbollah marked the anniversary of the assassination of former Quds Force commander Qassem Soleimani, Israel decided to violate the rules of confrontation with Lebanon, crossed the red line set by Hezbollah Secretary General Hassan Nasrallah several months ago and assassinated Saleh al-Aruri in an airstrike in Beirut's Dahiya quarter."

Hezbollah called the assassination "a heinous crime" that "will undoubtedly not go unanswered or unpunished."

Arouri was also expected to take part in negotiations for a new hostage release deal. According to reports, he was expected to meet with mediators next week in the ongoing negotiations for a hostage release in exchange for a cease-fire. Hamas announced the suspension of negotiations following Arouri's death.

Wednesday morning, Egypt also announced that it was ending mediation between Israel and Hamas following the assassination.