The Tokyo District Court on Tuesday sentenced a South Korean man to four years in prison over a fire at the Yasukuni Shrine last November.

Chon Chang-han, 28, damaged the ceiling of a public restroom at the shrine on Nov. 23 after igniting a gunpowder-filled metal pipe, the ruling said. An explosion was heard, but no one was hurt.

Judge Kazunori Karei said in the ruling that a lot of planning had gone into the crime as Chon made the gunpowder after researching it on the internet. He repeatedly tested it by filling metal pipes and igniting them.

"It was highly premeditated and atrocious in that, for instance, the device was put in a place where people could come and go freely," the judge said.

However, Karei stopped short of characterizing Chon's act as terrorism, a term prosecutors used in their closing arguments. The prosecutors said that Chon had carried out a "terrorist act based on a dangerous idea."

In one hearing, Chon told the court: "I thought South Korean media would praise (my acts). I had no intention of harming people."

Chon returned to South Korea on the afternoon of Nov. 23 but re-entered Japan on Dec. 9, bringing gunpowder with him. He was arrested upon arrival in Tokyo.

Prosecutors had sought a five-year prison term, while his defense counsel requested a suspended sentence.

After the ruling, Chon's defense lawyer expressed approval of the fact that the ruling did not use the word "terrorism" to describe the incident.

Yasukuni, a Shinto shrine that honors millions of war dead as well as Japanese leaders convicted of war crimes, is often seen as a symbol of the nation's militarist past by countries that suffered under Japanese occupation or colonialism before and during World War II, such as China and South Korea.