A group of women, who had spotted the intruder, tried to put out the raging flames in one of the holiest parts of the gurdwara, which was built at Bow in 1979. Most of the gurdwara's roof collapsed and worshipers fear all but one of its eight holy books have been destroyed, the Evening Standard newspaper reported.
Eye-witnesses described the suspected arsonist as being black or mixed-race. A worshiper said he had noticed racist graffiti on one of the gurdwara's outer walls in the past few weeks.
A criminal investigation has been launched and the police and fire investigators are treating the blaze as suspicious. The building, which dates back to 1854 was formerly a synagogue and before that a chapel.
The London Fire Brigade confirmed that 75 per cent of the building and the roof had been damaged by the fire. "Police are treating this incident as suspicious," a Metropolitan police spokesman was quoted as saying by the British daily.
Gurpal Singh, an eye-witness who visits the gurdwara regularly, said the attack was carried out "deliberately".
"Somebody did this deliberately. A man came in and got to the temple's holiest area. He was interrupted by one of the women, but managed to get away. As he ran out, the place went up in flames. Everyone panicked. The women tried to put out the fire, but it was too fierce," Gurpal, an IT worker from Chingford, was quoted as saying by the British paper.
35-year-old Gurpal said the women managed to save one of the holy books but the flames took hold before they could get to the other seven. "I can't describe how important those holy books were to the Sikh community," he added.
Kulvinder Singh Virk, 26, another member of the gurdwara, said: "This is very personal for us. It's as if a member of our family has been burnt to death."
Kamaljet Kaur, a 24-year-old from Stamford Hill, said her aunt was in the temple when the alleged arsonist struck. "The women thought he was a robber. It was only when they got upstairs that they discovered the fire raging," she said.
