Assassination of Saleh al-Arouri

Iran's top diplomat has warned U.N. chief Antonio Guterres that Tehran is ready for a "decisive and regretful" response if Israel attacks his country in retaliation for a missile attack.

Palestinian President Mahmoud Abbas has strongly condemned the assassination of Hamas leader Ismail Haniyeh in Tehran, according to Reuters. Following Haniyeh's death, which Hamas attributes to an Israeli attack on his residence, Palestinian nationalist and Islamic groups have called for a general strike and mass protests.

Hamas' political leader Ismail Haniyeh was killed in an Israeli strike in Iran on Wednesday, escalating tensions in the Middle East and prompted heightened global concern.

Hamas vowed the act "will not go unanswered," as its armed wing said Wednesday that the killing of its political leader takes the war with Israel to a "new levels," warning of repercussions for the entire region.

Ismail Haniyeh, the Hamas Political Bureau chief, has been killed in an attack in Tehran, Iran, as confirmed by the Islamic Revolutionary Guard Corps (IRGC) on Wednesday, according to Press TV. The IRGC, in a statement to Meher News Agency, reported that Haniyeh and one of his bodyguards were killed when their residence was targeted in Tehran.

Hamas said Wednesday its political leader, Ismail Haniyeh, was killed in an Israeli strike in Iran, where he had been attending the inauguration of the country's new president.