A US submarine this week torpedoing an Iranian warship during the Middle East conflict raised the crucial question of who controls the seas during wartime.

The sinking of IRIS Dena on Wednesday in international waters off the coast of Sri Lanka killed at least 86 crew members, in what Iranian Foreign Minister Abbas Araghchi labelled an "atrocity".

It came after US-Israeli strikes on Iran on Saturday triggered war in the Middle East, with the Islamic republic launching retaliatory attacks across the region and beyond.

The US Navy had not torpedoed a ship since 1945.

By Emma Farge

GENEVA, March 6 (Reuters) - The World Health Organization said on Friday that medical supplies in Gaza were running critically low despite Israel's reopening of a key crossing this week.

Supplies of some items such as gauze and needles have already run out, said WHO's regional director Hanan Balkhy, citing information from the Health Ministry in Gaza, devastated by the two-year Israel-Hamas war.

"Stocks of essential medicines, trauma supplies and surgical consumables are critically low, and fuel shortages continue to limit hospital operations," she said.

By Michele Kambas

NICOSIA, March 6 (Reuters) - A drone strike this week on a British air base in Cyprus has renewed calls for an end to British military presence on the Mediterranean island as many fear being dragged into the wider Iran conflict.

Cypriot politicians have long been uneasy with Britain's two air bases, Akrotiri and Dhekelia, which have existed as sovereign British territory since Cyprus gained independence from the United Kingdom in 1960.

Iranian drone strikes on Azerbaijan have raised fears that the Middle East war could spill into the Caucasus, as Baku, an ally of Israel, vows to respond.

Azerbaijan announced on Friday it was withdrawing diplomatic staff from Iran, a day after drones launched from Iranian territory targeted an airport and exploded near a school in the country's Nakhichevan exclave, bordering Iran.

Four people were wounded.

Israel’s air force has struck deep inside Iran with devastating precision, killing even the country’s supreme leader within minutes of the war’s outbreak -- a feat experts say reflects years of elite pilot training and combat experience.

"These pilots are the most trained in the world," Sarah-Masha Fainberg, a senior researcher on air and space military power at Tel Aviv University, told AFP.

By Jonathan Spicer, Feras Dalatey and Jonathan Saul

ISTANBUL/DAMASCUS/LONDON, March 6 (Reuters) - Turkey’s intelligence agency asked itsBritish counterpart MI6 last month to take a larger role in protecting Syrian President Ahmed al-Sharaa after recent assassination plots, according to five people familiar with the matter.

The request highlights efforts by foreign allies to shore up a country still shaken by sporadic violence 15 months after the overthrow of president Bashar al-Assad, with the U.S.-Israeli war on Iran now rattling the wider region.

By Emily Rose

JERUSALEM, March 6 (Reuters) - Israeli attacks against Lebanon's Iranian-backed Hezbollah group will likely continue after its joint air war with the U.S. against Iran ends, a source briefed on Israel's military strategy told Reuters, describing the two fronts as unconnected.

Israel warned Lebanon before the war that it would strike the country hard if Hezbollah, the most powerful of Iran's regional proxies, gets involved. On Monday, Hezbollah fired rockets at Israel, sparking Israeli strikes on Beirut's southern suburbs and Lebanon's east and south.

By Uditha Jayasinghe

GALLE, Sri Lanka, March 6 (Reuters) - Sri Lankan authorities said on Friday they were escorting a second Iranian naval vessel to harbour and moving 208 of its crew to a camp, two days after a U.S. submarine sank an Iranian warship in the same area.

President Anura Kumara Dissanayake said his island nation had a "humanitarian responsibility" to take in the crew, as the U.S. and Israeli war with Iran raged, wreaking havoc on global markets and disrupting trade and travel.

BEIRUT, March 6 (Reuters) - About 100,000 people have fled to shelters in Lebanon and the number of displaced is expected to rapidly increase following "unprecedented" Israeli warnings ordering people out of large parts of the country, a senior U.N. official said on Friday.

With war raging between Israel and Lebanon's Hezbollah, the Israeli military on Thursday ordered residents out of Beirut's southern suburbs, including areas controlled by the Iran-backed group, as well as parts of the eastern Bekaa Valley, after ordering people out of a swathe of south Lebanon on Wednesday.

GENEVA, March 6 (Reuters) - The U.N. refugee agency said on Friday that nearly 100,000 people have been displaced within Lebanon and tens of thousands of Syrian refugees there have fled back over the border, calling the situation in the region a "major humanitarian emergency".

Israel has issued large-scale evacuation orders for southern Lebanon and parts of Beirut amid hostilities with the Iran-backed Lebanese group Hezbollah since a U.S.-Israeli air campaign against Iran began on February 28.