A 33-year-old man charged with the murder of two French students in a frenzied knife attack last week has appeared in court.

Nigel Farmer, of no fixed address, is charged with the double murder as well as arson and attempting to pervert the course of justice.

He was remanded in custody by Greenwich magistrates until October 16 to appear at the Old Bailey.

Bio-engineering students Laurent Bonomo and Gabriel Ferez, both 23, were bound, gagged and repeatedly stabbed in Bonomo's south London apartment. Police called it the most frenzied, brutal and horrific murder they had investigated.

Bonomo was stabbed nearly 200 times, with up to 80 of the wounds inflicted after he was dead. Ferez had nearly 50 knife wounds. The killer or killers then set fire to the apartment in an attempt to destroy evidence.

Farmer turned himself in on Monday but was first taken to hospital to receive treatment for severe burns before police began questioning him.

Two other suspects, a 35-year-old man and a 25-year-old woman, were arrested on suspicion of murder on Wednesday and are being questioned at a London police station.

A man seen running away from the vicinity of the apartment on the night of the murders has been described by witnesses as white, aged between 30 and 40.

A laptop computer was stolen from the flat six days before the murders and Bonomo disturbed the intruder. Police at the weekend arrested a 21-year-old, but later released him without charge.

French newspapers said the murders highlighted how dangerous London has become. Police have arrested more than 1,200 people and seized more than 500 knives in a six-week crackdown against stabbings and knife crime in the capital.