London, Sep 22 - An Indian-origin woman was Tuesday sentenced to 33 years in jail - one of the longest jail terms handed out to a woman in Britain - for murdering her two teenaged daughters in a frenzied knife attack at her home in Cambridgeshire.

Rekha Kumari-Baker, 41, admitted killing Davina, 16, and Jasmine, 13, but denied premeditated murder on grounds of diminished responsibility - a defence that was rejected by the jury at Cambridge Crown Court after only 35 minutes of deliberation Monday.

The jury heard shocking details of how Kumari-Baker killed Davina and Jasmine with a kitchen knife as they lay sleeping in their beds June 2007.

The court heard there was 'much contention' between the defendant and her ex-husband David Baker over the care and custody of their children and how Kumari-Baker wanted to 'wreak havoc'.

In a savage attack, the mother stabbed Davina 39 times as the teenager fought to save herself. Jasmine, the younger sister, received fewer wounds because she succumbed to the attack more easily.

The jury was told the woman bought the knife June 11 - two days before she killed her daughters, siblings who were deeply attached to each other and whose photographs have been posted all over the internet.