TOKYO, Sept. 16 (Xinhuanet) -- Three people died and 24 were injured Tuesday in an explosion at an office in central Japan city Nagoya after a man armed with a knife took eight people hostage and sprayed liquid around the office.

　　According to Japan's national police agency, a massive explosion rocked the fourth-floor office of Nagoya-based courier company Keikyubin Co. at 1:10 p.m. (0410 GMT), only 10 minutes after seven of the hostages were freed.

　　The police identified the three victims as the 52-year-old suspect, an office manager and a police officer, the police said.

　　After the explosion, the entire floor was engulfed in flames and black smoke billowed from the shattered office, but the fire died down and was put out by 3:14 p.m. (0614 GMT)

　　There were 31 staff members in the office at the beginning of the incident when the suspect is alleged to have barged into the office at around 10 a.m. (0100 GMT)

　　The suspect earlier released 23 people before taking the eight remaining staff captive.

　　The suspect is believed to be a contract driver with the firm and was demanding unpaid wages from July to September, the police said.

　　According to Keikyubin representatives, the hostage-taker demanded 250,000 yen (2,136 US dollars), of which the July portion was scheduled to be paid on Saturday.

　　Keikyubin, established in 1986, is a franchise company that uses minivans and light vehicles for delivery. It has about 20 offices mainly in central Japan but also in Tokyo and Osaka. Enditem