A US man has confessed to raping and killing a fellow American tourist near Germany's famed Neuschwanstein Castle last June.

Troy Philipp B faces several charges, including one count of murder over a 21-year-old woman's death, and attempted murder of the victim's friend, a 22-year-old woman.

The 31-year also admitted to sexually assaulting the 21-year-old and pushing both women off a ravine.

He may be jailed for life if convicted.

"The accused committed the incomprehensible act," lawyer Philip Mueller said of his client on the first day of the trial at district court in the southern town of Kempten.

Lawyers denied the suspect acted with intent, telling the court that he acted spontaneously.

Mr Mueller said his client was "deeply ashamed" of his actions and wanted to apologise to her family.

B, who is from Michigan in the US, also admitted to possessing child pornography, which officials discovered during their investigation.

The two women met Troy Philipp B near the Marienbrücke bridge - a popular viewpoint used by tourists to view the castle.

He then led them to a hidden trail, on the pretext that the way to the bridge was difficult to navigate. Once in a secluded area, the man shoved the 21-year-old to the ground, raping and strangling her before the 22-year-old tried to stop him.

He then pushed the 22-year-old into the 50m deep (164ft) ravine and continued assaulting her friend, strangling her with a belt and recording it.

B then pushed the unconscious 21-year-old victim into the same ravine after some hikers came across the scene.

Mountain rescuers were able to the locate the women, but the 21-year-old woman died from her injuries in hospital. The 22-year-old suffered numerous injuries but survived.

The suspect was detained later that day after a massive police manhunt involving more than 25 vehicles.

A tourist from New York witnessed B being taken into custody and said his "face was covered in deep red scratch marks and his neck as well", adding "there was clearly a struggle".

The victims names have not released due to Germany's privacy laws.

Neuschwanstein Castle, in Bavaria, is one of the country's most popular tourist attractions, which sees over 1.3 million tourists each year.

Situated about 126km (78 miles) from Munich, it was built in the 19th Century and intended to serve as a residence for the rulers of the region, but was never occupied.