Is Israel attacking Greta Thunberg’s Gaza flotilla?

 First a flash of light, then flames rained down on the deck of the Alma, a British-flagged ship carrying aid to Gaza.

It was the second alleged attack in two days on the Global Sumud Flotilla, aboard which a coalition of activists, including Greta Thunberg, is attempting to break Israel’s naval blockade of the Gaza Strip.

On Monday, another vessel, the Family, was struck by what witnesses described as a fiery object dropped from a drone.

A day later, the Alma was struck by a similar projectile near the Sidi Bou Said port, off the coast of Tunisia.

The group posted videos of both incidents on Instagram, along with images of charred debris which they claimed was an “incendiary grenade wrapped in plastic materials dipped in fuel” that had been dropped by Israel in Tuesday’s incident.

It remains unclear what weapons, if any, were used in the alleged attacks, and who was behind them.

Footage from Tuesday night’s incident, which occurred as the flotilla docked in Tunisia, showed activists shouting “fire!” as an object crashed onto the deck, erupting in flames. For several moments the brightness of the blast filled the lens, before smoke drifted back into view.

The activists scrambled for extinguishers and brought the blaze under control after just a few seconds. All crew and passengers were unharmed, according to the flotilla.

The previous day, another fireball was filmed streaking through the night sky seconds before landing on the Family. Witnesses said a drone had been hovering overhead before the strike.

Analysts told The Telegraph the devices were likely to be incendiary or smoke grenades, rather than lethal munitions.

Noam Ostfeld, an intelligence analyst at Sibylline, said: “While it is impossible to be entirely certain about what the device is, it looks most likely it was a smoke grenade, but it could also have been an incendiary grenade. 

“The ordnance appears to be a metal device surrounded by a black and melted mass, likely plastic.”

He added that the plastic could have been part of a drone or might have been wrapped around a smoke grenade to cause a fire.

Mr Ostfeld said that the attack might have been the result of “a malfunction causing the item to fall from the air”, although it was also possible that “the intention was only to drop a smoke grenade onto the ship... either as a theatrical stunt or to intimidate”.

Wayne Montgomery, executive director of Sanborn Analytics, said he believed the incident was intended to send a message. “The intent seems to have been to intimidate rather than to cause harm. Israel remains acutely aware of the legal and operational implications of using lethal force against individuals aboard the flotilla,” he added.

Jorge Gómez, director of HSI Intelligence, said: “A drone armed with lethal weapons or a grenade would have done much more damage or resulted in the loss of life. It is a warning to the people on this flotilla.”

Those on board the flotilla are convinced that the first attack, which was similar to the second, was carried out using a drone.

Miguel Duarte, one of the activists, said: “The drone stood a few seconds on top of a bunch of life jackets and then dropped a bomb. 

“The bomb exploded and there was a big flame, there was a fire on board immediately. We picked up the fire extinguishers, we were able to fight the fire successfully and everybody was safe, fortunately.”

Thiago Avila, a Brazilian activist, later said: “It was 100 per cent a drone that dropped a bomb.”

The activists were also convinced Israel was responsible. Saif Abukeshek, a member of the flotilla’s steering committee, said: “Israel continues to breach international law and terrorise us. We will sail to break the blockade on Gaza no matter what they do.”

Israel has previously been filmed using incendiary devices in Gaza. Footage of an attack on an ambulance in Gaza City last week showed a similar streak of light in the sky before the vehicle caught fire, although The Telegraph has been unable to verify who was behind the attack.

The Israeli military has not commented on the alleged attacks. Tunisian authorities, however, cast doubt on the claims, saying reports of the first incident were “completely unfounded” and that the blaze may have been caused by a cigarette.

The Global Sumud Flotilla includes delegations from 44 countries, among them Ms Thunberg, the Swedish climate activist, Mariana Mortágua, a Portuguese politician and Ada Colau, the former Barcelona mayor.

The group has drawn significant attention from Israel, which has maintained a naval blockade of Gaza since 2007 to prevent weapons smuggling. 

In June, Israeli naval forces boarded and seized a British-flagged yacht carrying Ms Thunberg and others, alleging the voyage was a propaganda stunt in support of Hamas.

As the flotilla prepared to continue its voyage, its members insisted the attacks would not deter them. 

In a statement, the group said: “These repeat attacks come during intensified Israeli aggression on Palestinians in Gaza and are an orchestrated attempt to distract and derail our mission. The Global Sumud Flotilla continues undeterred.”