The accused identified as Amit, in his 20s, entered the house of the girls at around 8.30 am and initially attacked Srilekha (20), an engineering final-year student, with a knife and later attacked her elder sister Yamini Saraswathi (22), a BTech graduate, when she rushed to her rescue, police said.
"Both of them died at a hospital while undergoing treatment. Teams have been formed to nab the accused, who fled from the scene of offence," Deputy Commissioner of Police (DCP) Tafseer Iqbal told PTI.
A case was registered with Chaitanyapuri police station and a probe is on into the matter, police said.
