British planes helped Kurdish troops who were fighting ISIS in northwestern Iraq, dropping a bomb on an ISIS heavy weapon position and shooting a missileat an armed pickup truck, the UK's defense ministry said.
An initial assessment indicates both strikes were successful, according to the ministry.
British planes had been involved in reconnaissance missions over Iraq in the days since lawmakers approved UK airstrikes against ISIS in Iraq on Friday, but Tuesday's strikes were a first.
Britain joins the United States and France as countries that have hit ISIS in Iraq with airstrikes, while Belgium and Denmark have also said they also will provide planes. Of those nations, only the United States -- in partnership with some Arab countries -- have struck ISIS positions in neighboring Syria.
U.S. strikes as ISIS pressures Kurdish town in Syria
Meanwhile, ISIS -- the Islamic State in Iraq and Syria -- has continued to put pressure on a predominantly Kurdish town in northern Syria near the border with Turkey.
Rear Adm. John Kirby, spokesman for the Pentagon, said U.S. airstrikes overnight hit the town, Kobani, also known as Ayn al Arab.
A civilian inside Kobani told CNN on Monday that ISIS was closing in.
The terror group was three kilometers (nearly two miles) east of the town, the civilian said on the condition of anonymity, basically confirming a report from the Syrian Observatory for Human Rights, a London-based monitoring group.
If ISIS takes Kobani, it would control a complete swath of land from its self-declared capital of Raqqa to the Turkish border, more than 100 kilometers (60 miles) away. It has been fighting for months, capturing portions of northern and eastern Syria and western and northern Iraq for what it says is its new Islamic caliphate.
"My question is: why don't you attack ISIS near Kobani?" asked Rami Abdulrahman, founder and director of the Observatory.
When asked why strikes in the Kobani area may appear to be limited, a senior U.S. official said -- speaking separately on background -- that factors which may make it appear that way include that the United States has no direct reliable intelligence on the ground and that precise and careful targeting is needed to avoid civilian casualties.
The threat to Kobani has already led thousands of Syrians to seek refuge over Turkey's border.