Carrying Hamas flags, Palestinians in the city of Ramallah, near Arouri’s hometown of Aroura, chanted slogans such as "We will follow your footsteps" and "Revenge, revenge, Qassam!"
Al-Arouri was martyred as a result of an explosion in a building in al-Musharrafieh district in southern Beirut, Lebanon.
Later, Hamas confirmed that al-Arouri was killed in Israel’s terror attack, which also killed several of his companions.
Separately, protests were held at refugee camps, including the Beddawi camp in northern Lebanon, Anadolu Agency reported.
Carrying Palestinian flags and banners, groups chanted slogans condemning the crimes of the Israeli military and calling for support for the Resistance in the fight against the "enemy."
The National and Islamic Forces, a coalition of major Palestinian factions, also condemned the assassination of Arouri and called on Arab countries to take a "determined stance."
Arouri was the most senior Hamas leader to have been killed by Israel since the outbreak of the Gaza conflict on Oct. 7.
Israel has launched relentless air and ground attacks on the Gaza Strip since Oct. 7.
At least 22,185 Palestinians have since been killed and 57,035 others injured, according to Gaza’s health authorities, while nearly 1,200 Zionists are believed to have been killed in the Hamas operation.
The Israeli onslaught has left Gaza in ruins, with 60% of the enclave’s infrastructure damaged or destroyed and nearly 2 million residents displaced amid acute shortages of food, clean water, and medicines.
SD/PR