French authorities have detained a 15-year-old youth suspected of starting a forest fire that killed two firefighters, a source close to the investigation has told AFP.

The two firefighters were in a truck that became trapped by flames from a forest fire they were battling near Bordeaux airport, in western France, on July 21st.

The source said the teenager had been formally placed under investigation and held in juvenile detention.

The deaths, along with that of a volunteer firefigher battling another blaze in southeast France, angered French firefighter unions who say they do not have the resources to take on the many wildfires in the country this year.

Representatives of nine unions met Interior Minister Laurent Nunez on Thursday. They said the commitments he made were not enough and threatened industrial action in September.