By Maya Gebeily, Humeyra Pamuk and Alexander Cornwell

BEIRUT/WASHINGTON/TEL AVIV, March 7 (Reuters) - Israel and Iran traded attacks as the Middle East war entered a second week on Saturday, while Tehran made an unusual apology to neighbouring states, apparently seeking to calm regional anger at Iranian strikes on Gulf civilian targets.

"I personally apologise to neighbouring countries that were affected by Iran’s actions,” Iranian President Masoud Pezeshkian said, urging them not to join U.S.-Israeli attacks on Iran.

DUBAI, March 7 (Reuters) - Hardline clerics have called for the swift selection of a new supreme leader to help guide Iran, Iranian media reported on Saturday, as the Islamic Republic reels under a new wave of U.S. and Israeli strikes.

The calls suggest some in the clerical establishment may be uncomfortable leaving power in the hands of the three-man council put in charge temporarily after the killing of Supreme Leader Ayatollah Ali Khamenei, who had the final say in all matters of state.

Lion-emblazoned flags of pre-revolution Iran fluttered in cities across the world on Saturday as demonstrators took to the streets a week after the start of the war in the Middle East.

Europe, Africa and the Americas saw demonstrations, with some protesting against Iran's Islamic regime, others railing against the war, and some in support of Iran's late supreme leader Ali Khamenei, who was killed in the first US-Israeli strikes of the conflict.

BEIRUT, March 7 (Reuters) - When Israeli strikes began pummelling Beirut’s southern suburbs early on Monday, Sudanese refugee Ridina Muhammad and her family had no choice but to flee home on foot, eventually reaching the only shelter that would accept them: a church.

Eight months pregnant, Muhammad, 32, walked with her husband and three children for hours in the dark streets until they found a car to take them to the St. Joseph Tabaris Parish, which has opened its doors to refugees and migrants.

Two attack helicopters, their forward-facing guns silhouetted against Doha's clear blue sky, flew low over the city's cruise ship terminal as stranded passengers boarded buses and cars on Saturday for Riyadh, hoping to catch flights home.

"Eight days we are here in Doha and it's enough. We want to go home," Meral, 47, who lives near Dusseldorf told AFP as she and her partner Hussein, 52, wheeled their bags to a waiting private car to speed them to Saudi Arabia.

For a moment Tehran resembled a city at peace, with birdsong, joggers and tranquil views of the snow-capped Alborz mountains in the distance. Then the sound of another explosion ripped through the air.

A week ago, opening strikes by the US and Israel killed Iran's supreme leader Ayatollah Ali Khamenei, upended residents' lives and transformed the city streets into a battleground.

In Tehran's west, a block that belonged to the security forces had been blasted apart, and the entire surrounding area was choked with rubble.

DUBAI, March 7 (Reuters) - The president of the United Arab Emirates said his nation was in a time of war but was well and told his enemies it was no easy prey, in his first public comments since Iran launched missiles at its Gulf neighbour amid U.S.-Israeli strikes.

"The UAE has thick skin and bitter flesh - we are no easy prey," Mohammed bin Zayed Al Nahyan, who is also ruler of Abu Dhabi, said in comments, made on Friday when visiting those injured in strikes, aired on Abu Dhabi TV on Saturday.

The United States has started using British bases for certain operations against Iran during the Middle East war, the UK government announced Saturday.

Britain's defence ministry said the US had begun using the military sites for "specific defensive operations to prevent Iran firing missiles into the region".

Later Saturday, US President Donald Trump rejected what he said were British plans to possibly send two aircraft carriers to the region -- hours after having mocked Prime Minister Keir Starmer for his initial reluctance to get involved in the conflict.

With further negotiations pencilled in with the US and perhaps assuming that any assassination attempt would take place at night, Iranian supreme leader Ali Khamenei was at his complex in Tehran last Saturday morning. It would be his last.

An air strike obliterated the compound in Tehran where a gathering of key decision-makers was taking place, killing Khamenei, his wife and other top officials.

March 7 (Reuters) - Ukrainian manufacturers of cheap interceptor drones designed to knock out enemy unmanned aerial vehicles (UAVs) say they have the capacity to export in large volumes, amid enquiries from the United States and Middle East prompted by the Iran war.

Hundreds of drones based on Iran's Shahed model and now made in Russia fill Ukraine's skies during frequent attacks, and many are downed by air defences including Western missiles, fighter jets, truck-mounted guns and interceptor drones.