A man on Sunday set fire to an office in the main government complex in downtown Seoul and then jumped to his death.

The man identified by his surname Kim (61) was apparently able to walk into the complex, which houses eight government agencies including the Prime Minister's Office, using a fake ID.

Kim, who was being treated for depression, carried a backpack filled with flammable liquids, but metal detectors and other security systems at the complex were not running at the time.

Jongno police said the man, a former bank worker, set the fire to an office on the 18th floor of the complex at around 1:30 p.m. and jumped to his death. There were only nine people handling security that day. The fire burned only some papers and was extinguished in six minutes. There were no other casualties.

Kim (right) shows the fake ID to pass through a security gate in the government complex in downtown Seoul on Sunday. /Courtesy of Seoul Police Agency

According to police, Kim was laid off by a bank where he had worked for 20 years after the Asian financial crisis in 1999. He had been unable to find work since then and was carrying sedatives and barbiturates.

A friend told police Kim suffered from depression since being laid off. "He often told me he wanted to die," police quoted the friend as saying.

His family said Kim had delusions that he was a civil servant and wrote in one job application as a security guard that he used to work for the government.