BEIRUT - Lebanon's main grain silo at Beirut port was destroyed in a blast, leaving the nation with less than a month's reserves of the grain but still with enough flour to avoid a crisis, the economy minister said on Wednesday.

Raoul Nehme told Reuters a day after Tuesday's devastating explosion that Lebanon needed reserves for at least three months to ensure food security and was looking at other storage areas.

The explosion was the most powerful to rip through Beirut, a city torn apart by civil war three decades ago. The economy was already in meltdown before the blast, slowing grain imports as the nation struggled to find hard currency for purchases.

"There is no bread or flour crisis," the minister said. "We have enough inventory and boats on their way to cover the needs of Lebanon on the long term."

He said grain reserves in Lebanon's remaining silos stood at "a bit less than a month" but said the destroyed silos had only held 15,000 tonnes of the grain at the time, much less than capacity which one official put at 120,000 tonnes.

Beirut's port district was a mangled wreck, disabling the main entry point for imports to feed a nation of more than 6 million people.

Ahmed Tamer, the director of Tripoli port, Lebanon's second biggest facility, said his port did not have grain storage but cargoes could be taken to warehouses 2 km (about one mile) away.

"I want to reassure all Lebanese that we can receive the vessels," he said.

Alongside Tripoli, the ports of Saida, Selaata and Jiyeh were also equipped to handle grain, the economy minister said.

But former Deputy Prime Minister Ghassan Hasbani said other ports did not have the same capabilities.

Hani Bohsali, head of the importers' syndicate said: "We fear there will be a huge supply chain problem, unless there is an international consensus to save us."

Reserves of flour were sufficient to cover market needs for a month and a half and there were four ships carrying 28,000 tonnes of wheat heading to Lebanon, Ahmed Hattit, the head of the wheat importers union, told Al-Akhbar newspaper.

Lebanon is trying to transfer immediately four vessels carrying 25,000 tonnes of flour to the port in Tripoli, one official told LBCI news channel.

(Reporting by Ellen Francis, Tom Perry and Dahlia Nehme in Beirut and Maha El Dahan in Dubai; Writing by Nadine Awadalla; Editing by Veronica Brown, Edmund Blair and xx) ((Nadine.Awadalla@thomsonreuters.com;))