Michael Fallon
UK Defence Secretary Michael Fallon said strikes have hit Isis infrastructureGetty

British air strikes in Syria have seen "a fairly impressive start", UK Defence Secretary Michael Fallon has said. A week after the UK began bombing Islamic State (Isis) targets in war-torn Syria, Fallon said the extension of the campaign from neighbouring Iraq was a seamless transition.

Speaking to BBC Newsnight from Washington on 10 December, Fallon said that the number of missions have been doubled and take place on a daily basis. "We've already had some successful strikes on the infrastructure that supports Isil-Daesh (IS) from which it derives its revenue and from which, of course, it's been financing terrorist attacks in western Europe," Fallon said.

Fallon added that both laser-guided Paveway and Brimstone missiles were being deployed in the fight against IS, partly due to their ability to "minimise" civilian casualties. Last month, the Ministry of Defence (MoD) claimed that "there have been no known cases of civilian casualties resulting from UK strikes in Iraq". Earlier this week, the UK-based Syrian Observatory for Human Rights said that at least 26 civilians were killed by warplanes from the US-led coalition in the northeastern Syrian province of Hasakah.

The defence secretary said the Paveway and Brimstones can "deal very specifically with targets like oil wellheads, one particular building but not the buildings next door and it is that precision strikes that our allies really wanted us to bring to the campaign." He added that these munitions have been used in both Iraq and Syria to hit oil wellheads in a bid to stop the flow of money to the group.

The wealthiest terror organisation in the world, IS makes more than £52m (‎€73m, $80m) a month in revenue. In 2014, it made about £660m (‎€914bn, $1bn) in bank raids and an additional £660m through oil operations, taxes and kidnappings among other things, according to a CNN Money report.

"Where the RAF has come in specifically has been to add that precision strike – and I think we'll see more of that in the next days and weeks on depots, on logistics, on command and control headquarters, on the supply routes that run from Syria eastwards into Iraq itself" said Fallon.

Critics of the UK's participation in air strikes have said that the precision of the weaponry is only as effective as the intelligence on the ground. "Have we got people on the ground who are guiding us there?" Newsnight presenter Evan Davis asked the defence secretary. "Well not our people," said Fallon. "There are Kurdish forces fighting in northeast Syria against Isil-Daesh and we, of course, are providing an awful lot of the overhead surveillance – the intelligence and analysis in the skies above that helps more precise targeting."

When asked about the sustainability of strikes in Syria, Fallon said the RAF has been able to keep up the campaign in Iraq for over a year and that it can go on for "some time". He added "we plan to be there for a while".