Tense Beirut marks four years since port blast amid outcry over stalled justice

The explosion caused damage to a huge number of buildings in the area (Hussein Malla/AP)

Residents in Beirut are marking four years since a massive explosion in the port killed more than 200 people, as they live in fear of an escalation of violence in the region.

The blast anniversary on Sunday comes as the region braces for retaliation after an Israeli strike killed a senior Hezbollah commander in Beirut and an explosion in Tehran, widely blamed on Israel, killed top Hamas leader Ismail Haniyeh.