Thousands of Europeans were expected Saturday to rally in solidarity with refugees fleeing violence and war, as Hungary's populist premier said the migrants should come no further than camps around war-ravaged Syria's borders.

Dozens of events are planned with the biggest likely in London but there are also rival anti-migrant rallies expected, notably in eastern European countries that are resisting pressure to take in more of the refugees.

"I looked at the map and I decided to give it a go": Ahmad Taleb is one of a number of crafty refugees who have reached Europe by cycling across the border into Arctic Norway.

Norwegian police say that since the beginning of the year, more than 200 asylum seekers, the large majority of them fleeing the war in Syria, have crossed the border from Russia into wealthy Norway.

Australian aircraft have completed their first operation in Syria, defense officials said Saturday, just days after Canberra extended the mission from Iraq to better fight Islamic State jihadists.

"The Australian Air Task Group completed its first operational mission in Syria overnight, returning to base in the Middle East without incident," the defense department said in a statement.

Russia has issued an alert for Cyprus to divert aircraft from normal flight paths as it plans to conduct military exercises off the Syria' coast next week, officials on the island said Friday.

Reports in Moscow said Russia had sent NOTAMs (Notice to Airmen) to the U.S. Federal Aviation Administration about the exercises between the Syrian port of Tartus and Cyprus, about 100 kilometers (60 miles) away.

French jihadist David Drugeon was likely killed in a coalition strike in Syria in July, a U.S. official said Friday.

Drugeon, an alleged bombmaker, has been described as a key figure in the al-Qaida offshoot Khorasan group, which American officials say is a dangerous militant outfit planning to attack the United States and other Western countries.

A besieged area east of Syria's capital suffered one of its bloodiest months in August, with "intense" regime bombing attacks that killed and wounded hundreds, Doctors Without Borders said Friday.

MSF said "20 consecutive days of intense bombing attacks" on rebel-held Eastern Ghouta last month killed at least 377 people and wounded 1,932 others citing data from six hospitals.

An Islamist rebel group stormed Syria's largest prison on Friday, seizing two buildings in the complex near Damascus amid heavy fighting, the Syrian Observatory for Human Rights said.

"Jaish al-Islam entered Adra prison and seized two buildings in the women's section of the complex," said Observatory head Rami Abdel Rahman.

If France launches air strikes on Islamic State targets in Syria, it will follow the United States and Britain in claiming it is acting in self-defense, but experts say such action could land it in difficult legal territory.

In a marked change of strategy, France began surveillance flights over Syria on Tuesday with a view to launching strikes on the jihadists once targets have been identified.

Russia on Friday called for coordination between a U.S.-led coalition and Moscow to avoid "unintended incidents" in Syria where Washington accuses it of expanding its military presence.

In recent days Russia has faced criticism from the United States which says Moscow is ramping up its military presence in Syria in an apparent bid to prop up President Bashar Assad.

Disturbing footage emerged Friday of the way migrants are being treated inside Hungary's main refugee camp on the border with Serbia, with images showing families fed "like animals in a pen".

The video, shot secretly by an Austrian volunteer who visited the flashpoint Roszke camp on Wednesday, shows some 150 people wildly scrambling for bags of sandwiches thrown at them by Hungarian police wearing helmets and hygiene masks in a fenced-in enclosure inside a big hall.