A man stabbed his wife to death when she stepped in to save the "interfering" sister-in-law he knifed first, a court heard.

Ghulum Rasool Mirza, aged 35, of Cheetham Hill, Manchester, stabbed his wife Nilom nine times on October 3 last year, minutes after he had plunged a knife three times into her sister Nabila Mahmood.

Hours before the attacks Mirza unexpectedly handed in his notice at work, prosecutor Howard Bentham QC said at Manchester Crown Court.

In the evening he joined his wife at his sister-in-law's, where she was babysitting.

His wife sent him out to buy bread, but instead of going to the shop he went to their home nearby and returned armed with a 20cm knife.

He stabbed his sister-in-law in the back as she sat on the sofa. She fled upstairs, and his wife fought him to get the knife off him, before he stabbed her until the knife broke.

Judge Anthony Gee said Mirza tried to kill his sister-in-law because he believed "she had interfered in your life in some way".

He said Mirza's "loving wife" had died trying to protect her sister.

Judge Gee said he was in no doubt that Mirza would have killed her had it not been for the fact she fled upstairs and that his wife bravely intervened.

The court heard he was a hard working, quiet man, who had an arranged marriage in Pakistan with his wife 11 years earlier.

He had been diagnosed with mild depression and was prescribed anti-depressants three months before he killed.

Doctors who assessed Mirza, who claimed he was a devout Muslim, said that his fasting during the holy month of Ramadan may have contributed to his mental disturbance.

Mirza pleaded guilty to manslaughter with diminished responsibility of Nilom Mirza and guilty to the attempted murder of Nabila Mahmood.

Judge Gee gave him an indeterminate sentence for the public protection.

He sentenced him to life in prison on both counts, and said the minimum term he must serve before being considered for release on license was five years and 14 days.

Ahmer Nabi, the brother of the two victims, told the court Nilom was the family's "guardian angel" whose "heart was savagely cut to shreds with a carving knife without a second thought".

By Lucy Collins