Graffiti taggers are being urged to abandon plans to "bomb" railway lines this Saturday with tributes to the two men who died after being hit by a Tube train.

Comments have been posted on various forums by sprayers who plan to paint tributes in memory of Dan Elgar, 19, of Boscombe Road, Southend, and Bradley Chapman, 21, from Chafford Hundred, who died at Barking station last Friday.

Despite pleas from the pair's grieving families to stay off the railways, messages are appearing on web forums announcing plans to hit areas on Saturday.

One user of the Graffiti Forum, called Tubess, wrote: "Saturday is going to be jam 4 the soldiers the graf team have lost."

Another, Twisted, warns: "Watch what happens on Saturday."

But Keith Elgar, Dan's father, urged the young vandals to abandon their plans, saying: "It's hard to accept there are people wanting to put their own lives at risk to spray tribute to my son."

Dan Sanderson, 20, of Southend, a friend of Dan Elgar's who is a reformed graffiti artist, said it would be impossible to stop people from spraying tributes, but he urged them to do it legally.

He said: "I think people should take it to a legal wall and do a tribute there, because if you take it to a legal wall then you have got more time to do something good.

"I still think people will risk it. There is the buzz and people get addicted."

Rail company c2c said it was aware of the possibility of tribute graffiti and was looking to put on extra security guards at various sites and work more closely with the transport police.

The 25,000-volt overhead lines on the c2 line are switched on at all times, while London Underground operates on a third railway line running on 650 volts.