Two men appeared in court today charged with attempted murder after a man was stabbed, beaten with bricks and had sulphuric acid forced down his throat during an apparent "honour" attack.

The 24-year-old victim, believed to be a Danish man of Asian origin, is in a critical but stable condition in Broomfield hospital, Chelmsford, Essex. He is thought to have been blinded, to have suffered up to 50% burns and to have had his tongue destroyed in the attack, which took place in Leytonstone, east London, on 2 July.

Although the victim managed to raise the alarm after being set upon, by the time the emergency services reached him he was staggering around in agony and unable to speak properly.

Police have refused to comment on reports that officers have warned a married Muslim woman – who was allegedly having a relationship with the victim – that her life was now at risk.

The two suspects, who are aged 19 and 25 and come from east London but cannot be named for legal reasons, were remanded in custody after appearing at Waltham Forest magistrates court. They will appear at the Old Bailey on 30 September. Seven men were originally arrested, although five were released on bail. One of them, a 16-year-old, was rearrested yesterday.

Scotland Yard said: "At around 2am on July 2 a group approached a man in Marchant Road, Leytonstone. The group threw a noxious liquid over the 24-year-old victim before stabbing him twice in the back. The liquid caused serious burns to the victim's face and chest. He managed to escape and raise the alarm and an ambulance was called. He remains in hospital in a critical but stable condition."

When asked whether it was an "honour" attack, the police spokesman replied: "That is one line of inquiry but officers are keeping an open mind as to the motive."

Imtiaz Qadir, of the Active Change Foundation, said: "Honour crime happens a lot in our community, especially the Pakistani community, but we do try to educate the people." He told the London Evening Standard: "It's a cultural thing from back home. But this type of horrible crime is not exclusive to Muslims, there have been cases in other religions."

The police spokesman said the Met was "not prepared to discuss" reports the woman had been given an Osman warning – the name given to an official police warning that someone's life is under threat. They are usually given to alert potential victims of organised crime gangs. Between 2007 and 2008 the Met issued 75 warnings. The warning system was prompted by the police's failure to protect people from a psychotic teacher, Paul Paget-Lewis, who had shown signs of developing a worrying fixation with a former pupil, Ahmet Osman.

In 1988 Paget-Lewis shot and wounded Osman, and killed the boy's father and two others.