A “small, specialist team” is operating in Erbil, the capital of Iraq's autonomous Kurdistan region, training Peshmerga how to use the heavy machine guns Britain supplied in September.
The deployment was approved by Defense Secretary Michael Fallon, a ministry spokeswoman said.
“The government has previously made clear its intention to provide training to the Peshmerga as part of the continued effort to assist in the fight against ISIL (ISIS),” the spokeswoman said.
“The Defense Secretary has approved the deployment of a small, specialist team of non-combat army trainers which is now in the Erbil area providing instruction on operating, employing and maintaining the heavy machine guns that were gifted by the UK last month.”
The Sunday Times newspaper reported that the soldiers were from 2nd Battalion the Yorkshire Regiment, light role infantry whose headquarters are at the British sovereign base on Cyprus.
Royal Air Force Tornado jets have been taking part in bombing raids on ISIS targets in Iraq.
British Prime Minister David Cameron has ruled out putting "combat boots on the ground" in the campaign to defeat the extremist group.
British forces were part of the U.S.-led invasion of Iraq in 2003 that overthrew dictator Saddam Hussein. The last British combat troops left in 2009, with a small number staying on until 2011 to train Iraqi forces.
Germany has given assault rifles and portable anti-tank rocket launchers to Kurdish forces and German troops have also been in the Erbil area training them to use that new weaponry.
Meanwhile, British Foreign Secretary Philip Hammond arrived in Baghdad on Monday on an unannounced visit to Iraq.
Hammond has immediately held talks with Iraqi Prime Minister Haider Al-Abadi on British-Iraqi relations and international support for Iraq's war against the Islamic State in Iraq and the Levant (ISIL), Iraqi Foreign Minister Ibrahim Al-Jaafari's office said in a statement.
Source: AFP; Sunday Times