Protestors have staged an anti-drone demonstration outside RAF Waddington in Lincolnshire - home to the UK's Reaper fleet.
The unmanned aircraft, which carry 500lb bombs and Hellfire missiles for strikes on insurgents, began operations from the base in 2013.
Campaigners claim the systems are putting civilians at risk.
The MoD said it does everything possible to minimise the risk to human life from strikes.
The 39 Squadron moved to the UK base in 2013 but first started operating from Creech Air Force base, in Nevada, in 2007.
Christopher Cole, from the Drone Campaign Network, said the protest held earlier marked 10 years of UK involvement with drone operations.
He said it was about raising awareness of the issues surrounding drone warfare.
Mr Cole said the use of drones "made war too easy", and lowered the threshold for the use of force overseas.
He also questioned claims that there is no evidence of civilian casualties linked to UK drone operations.
"The idea they are precise and don't create civilian casualties is nonsense," he said.
According to campaigners, the UK has carried out more than 3,000 drone strikes in Iraq and Syria.
In a statement, the MoD said: "Given the ruthless and inhuman behaviour of our adversary, including the deliberate use of human shields, we must accept that the risk of inadvertent civilian casualties is ever present.
"We do everything we can to minimise the risk to human life from UK strikes."
It continued: "While we've not seen any evidence that we have caused civilian casualties, that isn't the same as saying we have not or will not do so, especially in close urban fighting against a ruthless terrorist enemy that uses civilians as human shields."