DENVER (REUTERS) - Federal authorities in Denver have arrested a woman accused of providing material support to Islamist insurgents fighting the governments of Syria and Iraq, and of conspiring to commit an offence against the United States, officials said on Wednesday.

According to a criminal complaint filed with US District Court in Colorado, Shannon Maureen Conley knew the group, the Islamic State of Iraq and the Levant, also known as ISIL or ISIS, was designated as a foreign terrorist organisation. The group renamed itself "Islamic State" at the weekend.

It said she met a co-conspirator, only identified as Y.M. in court papers, on the Internet sometime in 2013. It said the pair"shared their view of Islam as requiring participation in violent jihad against any non-believers", and Y.M. told her he was an active member of ISIL.

It said Conley planned to travel to Syria via Turkey to meet Y.M., and first attended military tactics and firearms training with the US Army Explorers in Texas in February of this year.

The court papers said the aim of the training was for Conley to provide support and help to ISIL fighters. It said she and Y.M. also planned for her to fight, if it was deemed necessary.