Fresh gunbattles erupted on Wednesday in the Libyan capital between two powerful armed groups, a security official said, a day after authorities declared the fighting over.

Clashes flared between the Radaa force and the 444 Brigade in key areas of the city, including the port, the source said.

Fighting eased towards the end of the day, according to television reports and residents who spoke to AFP, with some bakeries opening but schools remaining shut.

US President Donald Trump voiced hope on Wednesday that diplomatic efforts would succeed on Iran's nuclear programme, even as he vowed rigorous enforcement of sanctions.

Trump, on his first visit to the Middle East since returning to the White House, said he spoke about Iran with the leader of Qatar, which maintains relations with both longtime adversaries.

"It's been really an interesting situation. I have a feeling it's going to work out," Trump said of Iran after talks with the emir, Sheikh Tamim bin Hamad Al Thani.

Over 20 foreign nationals who themselves endured years of captivity in Iran on Wednesday urged Sweden to step up efforts to free a Swedish-Iranian citizen sentenced to death in the country, after he had a heart attack last week.

Ahmadreza Djalali, an academic who was sentenced to death in 2017 on espionage charges he denies, suffered a heart attack in Tehran's Evin prison, his wife said Friday.

The sound of fireworks and applause rang out in Syria's major cities overnight, as Syrians celebrated US President Donald Trump's decision to lift sanctions on the devastated country.

In Syria's second city Aleppo, dozens of men, women and children took to the central Saadallah al-Jabiri Square, waving the new Syrian flag and singing.

Hours earlier in Riyadh, Trump announced he would lift sanctions on Syria, as the country seeks to rebuild after the December ouster of longtime president Bashar al-Assad.

Gaza rescuers said at least 80 people were killed in Israeli bombardment across the Palestinian territory on Wednesday, as Israeli Prime Minister Benjamin Netanyahu spoke to US envoy Steve Witkoff about the release of hostages.

Negotiations for the release of the captives held in Gaza have been ongoing, with the latest talks taking place in the Qatari capital Doha, where US President Donald Trump was visiting on Wednesday.

Netanyahu's office said the premier had discussed with Witkoff and his negotiating team "the issue of the hostages and the missing".

Human Rights Watch on Wednesday said abuses were being committed on giant construction sites in Saudi Arabia and warned of the risks to migrant workers building stadiums for the 2034 World Cup.

HRW said "scores of migrant workers in Saudi Arabia die in gruesome yet avoidable workplace-related accidents, including falling from buildings, electrocution, and even decapitation".

US President Donald Trump landed in Doha Wednesday after visiting Riyadh, where he urged Syria's president to normalise with Israel after offering a major boost to the war-ravaged country by vowing to lift sanctions.

Trump became the first US president in 25 years to meet a Syrian leader -- Ahmed al-Sharaa, an erstwhile Islamist guerrilla and onetime jihadist who had been on a US wanted list and led the overthrow of Bashar al-Assad in December.

United Nations relief chief Tom Fletcher on Tuesday called on the UN Security Council to take action "to prevent genocide" in Gaza, delivering a scathing account of Israel's actions in the Palestinian territory.

Fletcher, the UN Under-Secretary-General for Humanitarian Affairs, demanded that Israel lift its aid blockade on Gaza, where its offensive has killed tens of thousands and reduced much of the enclave to rubble.

Rights groups on Tuesday urged judges to halt Britain's supply of fighter jet parts to Israel amid the war in Gaza, as they took the government to court and accused it of breaking international law.

Supported by Amnesty, Human Rights Watch, Oxfam and others, the Palestinian rights association Al-Haq is seeking a court order to stop the government's export of UK-made components for Lockheed Martin F-35 fighter jets.

Israel has used the US warplanes to devastating effect in Gaza and the West Bank.

Human Rights Watch on Wednesday said grave abuses were being committed on giant construction sites in Saudi Arabia and warned the risks to migrant workers could increase as the building of stadiums for the 2034 World Cup gathers pace.

HRW said "scores of migrant workers in Saudi Arabia die in gruesome yet avoidable workplace-related accidents, including falling from buildings, electrocution, and even decapitation".