“Mourners in Iran and Lebanon commemorated slain militant leaders Thursday, as they vowed retribution against common enemy Israel and signaled that the most recent paroxysm of violence gripping the Middle East may be far from over. Thousands of people, some waving Palestinian and Iranian flags, joined a funeral procession in the Iranian capital for Hamas leader Ismail Haniyeh, who was killed a day earlier in a murky attack in Tehran. In a Beirut suburb, hundreds of fighters, supporters and dignitaries also gathered for the funeral of Fuad Shukr, a senior Hezbollah commander Israel targeted in an airstrike Tuesday night. Iranian officials have accused Israel of conducting the operation that killed Haniyeh, who was the group’s top political operative, and vowed revenge. Iran said Haniyeh, who was visiting Tehran for the inauguration of its new president, was hit by a “projectile” on the fourth floor of the building where he was staying in the northern part of the city.”