(CNN) -- A Comic-Con attendee stabbed another near the eye with a pen Saturday after they got into an argument over whether one was sitting too close to the other, police said.
The injured man, in his 20s, was taken to a hospital with a minor cut, said San Diego Police Officer David Stafford. The attacker, also in his 20s, was arrested and booked for assault with a deadly weapon, he said.
The incident took place in the San Diego Convention Center while fans were waiting for a panel featuring actor Seth Rogen discussing the science-fiction comedy "Paul."
"The room was very crowded and the males argued over one male sitting too close to the other," Stafford said.
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The suspect was later seen being led away in handcuffs. He had on a blue "Harry Potter" T-shirt.
The panel was delayed for about 30 minutes while attendees were shown a series of movie trailers.
"Well, there is a crowd issue. It's gotten really crowded. And if anything, an incident like this points to the need for more space," convention-goer Zennie Abraham told iReport -- the CNN website that allows people to submit pictures and videos.
"Should Comic-Con be in San Diego? I think so, but San Diego's got to make more space for it. It's become too big and I didn't think anything like this could happen because it's a chill event but it did happen."
Comic-Con, the annual gathering of self-proclaimed fanboys and fangirls, began Thursday and concludes Sunday. Aside from the stabbing, the convention has proceeded without incident so far, Stafford said.
