Khun krabii hiiroh (2004)

The fourth generation of the virus SARS is found in Africa! It's more dangerous and causes the patients to transform into bloodthirsty zombies. The virus quickly lands to Thailand, Dr. Bryan Thompson who creates the anti-virus, ends up getting infected while doing his experiment and soon the virus is spreading to all the residents of his same building. At that time, Khun is trying to help a young girl who's being kidnapped in the building... He ends up trapped in the building with only his precious sword as a weapon. Surrounded by the zombies, he has to find the girl and escape from the building before the government drops a bomb to destroy the virus and the building.