Al-Qaeda

Captain Jeff Davis, a spokesman, said 10 operatives were killed in a single strike on 3 February.

A second strike on 4 February killed Abu Hani al-Masri, who had close ties to the late al-Qaeda leader, he said.

Al-Masri is said to have set up and run al-Qaeda training camps in Afghanistan during the 1980s and 1990s.

He also had close ties to Ayman al-Zawahiri, who became the leader of al-Qaeda when Bin Laden was killed by US forces in 2011.

Twenty-eight of them were slain by Islamic militant groups, including al-Qaeda and the Islamic State group, according to the Committee to Protect Journalists.

The New York-based organization says Syria again was the deadliest place for journalists, though the number of deaths there in 2015 — 13 — was lower than in previous years of the conflict.

Hamza bin Laden, believed to be in his mid-20s and reportedly known as the ‘crown prince of terror’, has been touted as a future leader of al-Qaeda.

In the message, which was shared on Twitter, he calls for lone wolf jihadist attacks on America and its allies and marks out London, Washington, Paris and Tel Aviv as specific  targets.

The message made no mention of Isis.

Rita Katz, director of Site, a terror intelligence group, tweeted: "Hamza Bin Laden, son of Usamah bin Laden [sic], gives strategies in continuing global jihad in audio message.