RAF aircraft carried out four missions against the Islamic State (IS) group in Syria on Sunday, using Brimstone missiles for the first time.
The strikes targeted a vehicle near Raqqa - a stronghold of IS - as well as the Omar oilfield in the east of Syria, said Downing Street.
Defence Secretary Michael Fallon said the UK was "playing a key role" in the fight against IS, also known as Daesh.
Brimstone missiles are radar-guided and can be used against moving targets.
The RAF has carried out several strikes in Syria since MPs voted in favour of extending UK action into the country on 2 December.
In the four missions which took place on Sunday:
- Two Tornado jets used a Brimstone missile to destroy a supply truck near Raqqa, and Paveway IV laser-guided bombs to target two IS buildings, including a command and control centre
- Reaper unmanned drones targeted an IS position in the Raqqa area with a Hellfire missile
- Two Tornados struck a tunnel complex near Raqqa with four Paveway bombs
- Two Tornados and a Reaper drone used three Brimstones, as well as Hellfire missiles, to attack a number of mobile cranes brought in by IS to the Omar oilfield to try to repair damage inflicted by previous air strikes.
Asked whether these latest missions indicated the UK was stepping up its fight against IS in Syria, Prime Minister David Cameron's official spokeswoman said: "This is part of the ongoing operation and work we are doing with coalition partners to defeat Daesh in Iraq and Syria.
"We have always been clear that it is going to take time and require patience and persistence, but it reflects the fact that where we identify targets and an ability to strike them, we will do all we can to tackle Daesh."
'Maintain this tempo'
RAF activity has been focused on Iraq rather than Syria - most recently in the battle for Ramadi.
The MoD said there were a number of missions over Iraq last week, supporting troops on the ground, including destroying two machine-gun positions and two armoured personnel carriers near Ramadi.
The defence secretary said: "Britain is playing a key role in the fight against Daesh, whether helping Iraqi ground forces retake Ramadi or by striking targets near its Raqqa heartland.
"Our Reaper drones have now flown 1,000 missions against Daesh and we will maintain this tempo with RAF pilots flying day and night over Iraq and Syria."
Mr Fallon said he would meet other coalition defence ministers next week "to plan the next stage of the strategy".
He added: "The Royal Navy continues to support our allies as HMS St Albans will shortly join the Charles de Gaulle aircraft carrier group as we unite to destroy Daesh."
An MoD spokesman said the frigate, which is already on deployment in the Gulf, had been called up as the next ship to protect France's aircraft carrier.
Brimstone missiles are billed as the "most accurate precision strike product on the market", radar-guided and able to be used against targets moving at up to 70mph.
The UK and Saudi Arabia are the only two countries to have purchased Brimstones, and while laying out his case for British action against IS in Syria, Mr Cameron argued that their use would make a "meaningful difference" to the battle.
Meanwhile, the UK is helping to fund a United Nations mission to deliver aid to the besieged Syrian town of Madaya, where there are reports of people starving to death.
The Department for International Development said UK money would help provide food parcels, nutritional supplements, essential drugs and non-food items, such as tents, for up to 40,000 people.