June 21 (Reuters) - Fifty-four people have been injured while 18 are missing after an explosion at Qatar's core liquefied natural gas processing site of Ras Laffan on Sunday, authorities said.

An incident during the start-up of operations at Ras Laffan Industrial City resulted in an explosion and fire at the Barzan local gas supply facility on Sunday evening, QatarEnergy said in a statement. Emergency response teams were deployed to contain the fire, which was now under control, it said.

Iran and the United States wrapped up the first round of talks to end the Middle East war at the Burgenstock resort in Switzerland on Monday, with technical talks to continue.

Iran's Foreign Minister Abbas Araghchi hailed the "major progress" achieved with the help of mediators Pakistan and Qatar, while the United States government has yet to issue a statement.

Here are the main points from the joint Qatar-Pakistan statement at the conclusion of first-round talks:

- Roadmap to final deal agreed -

SEOUL, June 22 (Reuters) - Two vessels operated by South Korea passed through the Strait of Hormuz after the U.S. and Iran signed a memorandum of understanding on a ceasefire agreement last week, Seoul's Ministry of Oceans and Fisheries said on Monday.

The vessels are sailing normally, but have not yet fully exited a high-risk zone, the ministry said, declining to disclose further details on the vessels.

The ships do not have South Korean crew on board and are not bound for South Korea, the ministry said.

By Humeyra Pamuk, Dave Graham and Tala Ramadan

BUERGENSTOCK, Switzerland/DUBAI, June 22 (Reuters) - Iran-U.S. peace talks in Switzerland stretched into their second day on Monday, after a tense opening marked by Tehran's announcement it had again closed the Strait of Hormuz and U.S. President Donald Trump repeating his threats to resume attacks on Iran.

By Florence Tan

SINGAPORE, June 22 (Reuters) - The number of ships that passed through the Strait of Hormuz fell sharply on Sunday after Iran announced it had again closed the waterway, citing Israeli and U.S. violations of the interim peace deal, shipping data showed.

Hundreds of football fans gathered beneath the towering bookshelves of Tehran Book Garden on Sunday night to watch Iran take on Belgium in the World Cup.

Unlike many national teams whose supporters rally unquestioningly behind them however, Team Melli arrived at kickoff carrying the weight of deep divisions at home.

Inside the sprawling cultural complex, families, students, pensioners and young couples filled rows of seats facing giant screens broadcasting the match from the United States.

Syrian President Ahmed al-Sharaa denied on Sunday that his country sought to intervene militarily in Lebanon where Israel and Hezbollah are at war, after US President Donald Trump repeatedly suggested Damascus could get involved.

"We are looking for economic channels between Lebanon and Syria, not military ones," Sharaa said in an interview broadcast on television channel Al Mashhad.

On Sunday, Trump told Fox News he was "disappointed Israel can't put Hezbollah away", adding in reference to the fight against the militant group: "I'm close to giving it over to Syria."

CAIRO, June 21 (Reuters) - Hezbollah chief Naim Qassem said on Sunday that Israel will not stay in Lebanon, adding that the group would respond to any violation from the Israeli side.

His statements came as Israeli officials say that troops are free to act without restriction to eliminate threats in Lebanon despite an agreed ceasefire that took effect on Friday.

(Reporting by Menna Alaa El-Din and Ahmed Tolba; Editing by Alexandra Hudson)

The uber-plush Burgenstock resort perched high above Switzerland's Lake Lucerne -- the dramatic setting for Sunday's US-Iran talks -- is well-accustomed to hosting world leaders, movie icons and peace negotiations.

The luxurious hotel complex was proposed by Washington and Tehran, and their Pakistani and Qatari mediators, for the negotiations aimed at fleshing out their preliminary agreement on ending nearly four months of war.

The tranquil and picturesque location is hard to access, with water on three sides, and is therefore easy to seal off for major events.

By Sergio Non

WASHINGTON, June 21 (Reuters) - President Donald Trump on Sunday posted that the U.S. will resume attacks on Iran unless the Iranians can keep their Hezbollah allies in Lebanon from causing violence.

"Iran must immediately stop their highly paid PROXIES in Lebanon from causing trouble," Trump wrote on Truth Social. "If they don’t, we’ll hit Iran very hard again, just like we did last week, only harder!!!"

(Reporting by Sergio Non; Editing by Mark Porter)