A suspicious man caught on surveillance cameras after an explosion was heard outside a public restroom at the war-linked Yasukuni Shrine in Tokyo on the morning of November 23 is South Korean and has returned to South Korea, investigative sources said on Wednesday. Security cameras around the restroom captured a man in dark clothes wearing eyeglasses and carrying a backpack and a bag approximately 30 minutes before the sound of the blast at the shrine that is seen as a symbol of Japan's militarist past in China and South Korea. The Metropolitan Police Department (MPD) has been studying the possible trail of the man by analysing video footage and examining whether the man is linked with the possible explosion incident, which caused no injuries. READ MORE: Blast damages public restroom at Japan’s controversial Yasukuni shrine for war dead The sources said some items left behind at one of the stalls of the restroom had Korean Hangul writing on them. According to the sources, the man headed for the restroom where the blast was heard. Subsequent footage from the shrine showed him without a bag, exiting the compound by the nearby South Gate and walking toward the Kudanshita subway station. The MPD also checked videos from security cameras in the neighbourhood of the shrine in Tokyo’s Chiyoda Ward and found that the man did not use the station but walked to a hotel in the same ward, the sources said, adding that the police found out that the man then left for South Korea. The blast sound was heard at around 10am. About 100 people were visiting the main hall for a religious festival just starting. It came at a time when Japanese police stepped up vigilance in the capital following the terror attacks in Paris 10 days earlier. The ceiling of a stall in the men’s restroom had a square hole measuring about 30cm on each side and a bundle of four metal pipes was found in the ceiling, the sources said. The pipes contained a granular substance presumed to be gunpowder, with three of them nearly emptied apparently after combustion, they said. On the floor of the stall was a digital timer with a wire lead attached to a battery case, the sources said. Batteries were also left scattered around. The MPD suspects that a handmade explosive device may have fizzled and is looking into the structure of the device and the substance. The shrine triggers a diplomatic outcry from China and South Korea whenever high-ranking Japanese politicians pay homage there, after it added Class A war criminals to its honour list in the late 1970s along with around 2.5 million war dead. It has been targeted for attacks in the past including a suspected arson by a Chinese man who is alleged to have poured gasoline on a gate post at the shrine in December 2011. In December last year, a Japanese man was arrested after an attempted self-immolation on the shrine’s premises. On Thursday, South Korea said it would consider handling the case of a South Korean man reportedly suspected of involvement in an explosion last month at the war-linked Yasukuni Shrine in Tokyo based on “law and procedures” if Japan were to hand over the suspect, Seoul’s Foreign Ministry spokesman said. “At the moment, it's our understanding the suspect has not been specified,” Cho Joon-hyeok said during a news briefing. He also said the Japanese government has not informed South Korea of the outcome of investigations nor asked for cooperation on the case.