Two graduate students have been arrested for sitting around a traditional Japanese heated table they set up at the center of a busy intersection in western Japan, police said Wednesday.

Masako Ueda, a 31-year-old student at Kyoto University's graduate school, and fellow 26-year-old student Masatoshi Kato were arrested on suspicion of obstructing traffic. The motivation for their stunt is unknown.

On the evening of Feb. 25, Ueda and Kato allegedly set up the kotatsu, a square table common in many Japanese households, with a hot pot cooker on top.

Ueda, Kato and two other people sat around the kotatsu for more than 10 minutes at the intersection near the university. After rushing to the scene, police warned them to move along and the group loaded the table on a handcart and carried back to the university campus.

Considering it a "very dangerous action" that could have caused a serious accident, police have judged it as a violation of the road traffic law.

Based on dashboard camera footage and other sources of information, Ueda and Kato were the only ones identified among the four people involved. The police are still trying to determine the identities of the other two.