"We sympathize with the dear citizens of #Lebanon and stand by them in the painful tragedy of the explosion in Beirut port, which killed and injured a large number of people and caused severe damage. Patience in the face of this tragedy will be a golden page in Lebanon’s honor," Ayatollah Khamenei's Twitter account said on Wednesday.
The explosion, so powerful it could be felt more than 150 miles away in Cyprus, rocked the Lebanese capital, Beirut, on Tuesday evening, killing over 100 people and injuring more than 4,000 others.
The explosion leveled whole sections of the city near the port of Beirut, leaving nothing but twisted metal and debris for blocks in the capital's downtown business district.
With an untold number still missing, officials expect that the casualties are highly likely to rise amid the city's overwhelmed hospitals.
President Michel Aoun said earlier that the blast was caused by 2,750 tonnes of ammonium nitrate stored unsafely in a warehouse.
Meanwhile, security forces have imposed house arrest on anyone involved in the storage of ammonium nitrate at the port while the investigation into the explosion continues.
The government’s minister of information, Manal Abdel Samad Najd, said after a Wednesday cabinet meeting that the country would enter a two-week state of emergency,
Lebanon has announced three days of mourning.