Britain's defense secretary says U.K. fighter jets have targeted a Syrian oilfield during a second combat operation against the Islamic State group.

Michael Fallon says the four jets from the British base in Cyprus bombed wellheads at the Omar oilfield in eastern Syria. Late Friday's operation, which aimed to cut off the militants' oil revenues, followed a similar strike the day before.

The bombing began hours after British lawmakers voted Wednesday to expand Britain's air campaign against IS in Iraq to Syria.

Fallon told military personnel in Cyprus: "We are going to use force against them in the headquarters, their command and control, their logistics, but also in the infrastructure that supports them."

He says the fight against IS will not be "either short or simple."