THE family of a teenager stabbed to death at home in front of his parents fear his murderers will strike again if they are not caught soon.

Aamir Siddiqi, 17, was stabbed to death after opening the door to two masked men at his home in Ninian Road, Cardiff.

His parents, aged 55 and 68, were also stabbed by the attackers as they rushed to help their teenage son on Sunday afternoon.

Both suffered serious stab wounds to the torso as they tried to fight off the two men. Both were taken to hospital for treatment and have since been released.

In a statement released yesterday, they paid tribute to their son describing him as "a kind and sensitive gentleman’’.

Police said today that the teenager may have been the victim of mistaken identity.

That is one line of inquiry that they are looking at to explain what otherwise appears to be a motiveless attack.

Nishat Siddiqi, 34, one of the teenager's three sisters, appealed to the public today to come forward if they have any information.

In a press conference at Cardiff Central police station, she spoke of her family's fear that the killers will strike again if they are not caught soon.

"We also want everyone to remain calm. We are afraid in our own family that the people who committed this crime may do so again,’’ she said. "If anybody has any information, then they should pass this on to the police.

"Please help so that these perpetrators are found before they harm anyone else,’’ she said.

Also present at the press conference were sisters Umbareen Siddiqi, 30, and Mirium Siddiqi.

An uncle of the murdered teenager was also present and made a similar public appeal in Urdu.

Detective Chief Superintendent Stuart McKenzie, who is leading the investigation, described the murder as "horrific’’.

He said that the police have found no motive which could explain the attack on the teenager.

He said: "He was an upstanding member of the community. He was an avid sports fan and scheduled to go to university in the autumn. We have no motive.

"One hypothesis is that Aamir was mistakenly targeted. We cannot understand why he was targeted.’’ He added that there was also no evidence that the attack was in any way racially motivated.

He said that South Wales Police had designated the murder a "critical incident’’ and a staff of 60 officers was working on it.

One of the two men is described as being of Asian appearance, in his late 20s, of average height and stocky build, with dark hair. He was wearing dark clothing.

The second man is described as being of Asian appearance, in his early 20s, about 5ft 11in and of slim build. He was wearing a white jacket with a grey stripe down the sleeves.

As they were leaving the area they were seen to be pulling black knitted balaclavas over their faces, police said.

Witnesses or anyone with information have been asked to contact the incident room at Cardiff Central police station on 02920 571530 or Crimestoppers anonymously on 0800 555 111.