SHANGHAI, Nov. 1 -- A JEALOUS lover who killed his girlfriend's grandmother and then told her mother to leap from a third-story window has been formally arrested by Zhabei District prosecutors.

Zhang Jie, 24, will face a charge of murder after he went berserk at his girlfriend's home on July 6.

Prosecutors say Zhang, who was unemployed after graduating from a technical secondary school, saw his girlfriend, Li, end their affair in June.

Two weeks after they broke up Zhang went to Li's home at 3am saying he had to pick up his belongings.

Li was not at home - there was just her mother and grandmother who let Zhang in. The angry young man then began storming in and out of Li's room, saying he could not find any of his things.

Li's mother had enough and ordered him out which provoked Zhang even further.

As he got angrier with her, the mother retreated in fear into Li's room shouting for help from the grandmother. As grandmother tried to stand up to the man while the police were being called, Zhang cracked, rushed into the kitchen, grabbed a knife and slashed the grandmother about the head and shoulders, killing her on the spot.

He then returned to Li's room, waved the bloody knife at her mother and shouted that it was now her turn to die.

He told her he had opened the gas taps and if the police arrived and opened the door there would be a huge explosion in the apartment. He raged through the house, smashing furniture, a television and a telephone, and then he held the knife up to the mother and ordered her to jump from the window.

Just as she climbed in fear onto the window ledge, police broke down the door and rescued her, alas too late to save the grandmother.