BEIJING (Reuters) - A Chinese woman in her 60s has handed in weapons and ammunition to police after 30 years of agonizing over what do with them, Xinhua news agency said on Tuesday.

The woman, surnamed Li, told police in southern Hainan Island she had a cache of weapons and ammunition to turn over -- four grenades, a rifle and 165 bullets hidden in a wardrobe and in a book cabinet.

She decided to hand in her home arsenal after seeing a government announcement banning the possession of weapons.

"She worried if the weaponry was stolen, it might cause trouble," Xinhua said, "Li said she has been worrying about it for the past 30 years, and now she could rest at ease."

The police were looking for the source of the weapons, the news agency said, but did not say how they came into Li's possession.