Six Tornado jets have been based in Cyprus since last month but had been restricted to reconnaissance flights. The RAF also has a Rivet Joint spy plane in the region, which is stepping up surveillance efforts to identify potential targets, while intelligence will also be sought from Iraqi and Kurdish forces on the ground.
The Tornadoes joined the US Air Force and jets from regional states in flying rotations over the north and centre of Iraq while targets were nominated for them to strike. A small number of SAS troops have been on the ground with US special forces for more than a month helping select targets and guide in bombs. Britain entered the fray more than seven weeks after the US first sent fighter jets to defend the Kurds of northern Iraq from an Isis advance and one week after France, Saudi Arabia, the UAE, Bahrain, Jordan and Qatar sent their air forces to attack targets inside Syria. Denmark and Belgium have also committed their air forces to tackling Isis, but, like Britain and France, have limited their roles to inside Iraq. Isis controls a swathe of land from the eastern edge of Aleppo to the northern fringes of Baghdad.
Cameron gave no indication of how long the RAF would remain involved and said he was undecided about whether to extend the mission to Syria.
Watch: Obama scores Coalition victory with strikes
Hundreds of Isis sympathisers in the UK could delay or halt plans to travel to Syria and Iraq and instead choose to launch attacks on home soil in direct response to the decision to begin air strikes in the Middle East, experts have warned.
Analysts from the International Centre for the Study of Radicalisation and Political Violence said they had identified a cohort of Isis supporters numbering several hundred, whom they classified as "fanboys", and who they believe might now stay in the UK rather than fight abroad.
Professor Peter Neumann, director of the centre, said the MPs' vote for air strikes in Iraq had, in the minds of some Isis supporters, moved the frontline from Syria and Iraq to Britain. Neumann said the intervention in Iraq would pose new logistical challenges for intelligence agencies. "The problem is that you are dealing with several hundred people. It becomes a capacity problem. One cannot follow that many people day and night. The problem is that if you do a relatively low-cost operation, take a big knife and behead someone on the spur of the moment, it's very difficult to stop."
Hit squad
*Royal Air Force Tornado GR4 jets armed with laser-guided bombs took off from Britain's RAF Akrotiri base on Cyprus for missions over Iraq but returned (below) after seven hours without having used their weapons.
*Seven targets were hit in Syria, the Pentagon said, including an Isis building and two armed vehicles in Kobane.
*The Syrian Observatory for Human Rights monitoring group said Isis rockets also hit the town, wounding 12 people.
*Other targets in Syria included Isis vehicles and buildings near Al-Hasakeh, as well as an Isis command and control facility near Minbej, US Central Command said.
*Senior Syrian Kurdish official Newaf Khalil said the latest strikes hit the Isis-held town of Ali Shar, east of Kobane, and destroyed several Isis tanks.
*Turkish President Recep Tayyip Erdogan said Turkey could take a military role in the coalition.
*Coalition aircraft also pounded the Euphrates city of Raqqa.
- Observer, AFP
