LITTLETON (Colorado). May 4: A 22-year-old man was arrested on suspicion of supplying the Columbine High School gunmen with a semiautomatic handgun, one of four weapons used in their rampage, reports AP.

The arrest came Monday as Columbine students returned to classes at another school,' nearly two weeks after the massacre that left 15 dead.

Mark Manes of Littleton was booked for investigation of providing a handgun to a minor. a charge that carries a maximum six years in prison. He was released on bond.

Police said they do not know if Manes knew what the gun would be used for. but an attorney for Manes said his client knew nothing of the impending massacre.

"He was horrified when it happened." attorney Robert Ransome said. "I would like to say he has followed the path of integrity from the beginning."

Manes, who once attended Columbine, was the first person since the April 20 shootings to be arrested on charges of helping Eric Harris, 18, and Dylan Klebold, 17, arm themselves and assemble more than 50 bombs.

The only other arrest in the case is that of a man accused of lying about the two teens having bought possible bomb supplies at a hardware store. Police are still trying to determine if others had a hand in the killings.

"They've always, from day one. had a feeling that there had to be some people who had some knowledge or helped them plan or build some of these bombs." Jefferson County sheriff's spokesman Steve Davis said. "I think they're still leaning that way."

Investigators said an employee at the pizza parlour where Harris and Klebold worked put the two teen-agers in touch with Manes and a TEC DC-9 semiautomatic pistol.

"He was the last person who had it before it was supplied to one of our gunmen." Davis said.