The scaffolding on the highrise that the thieves climbed to clean out the apartment. Picture by Sanjoy Chattopadhyaya

Two robberies in highrises were reported on Thursday, in one of which the criminals entered a ninth-floor apartment by climbing up a scaffolding at the rear of the building.

Cash and jewellery worth more than Rs 5 lakh were looted from the two apartments. No one has been arrested, though police suspect the involvement of a domestic help in one of the cases.

The break-in at the ninth-floor apartment on AJC Bose Road came to light on Thursday, when the owners returned from Delhi. Jewellery worth Rs 3.5 lakh and Rs 1.5 lakh in cash were missing from an almirah.

The dacoity took place between Saturday, when the Guptas, who own the apartment, left for Delhi, and Wednesday night, said an officer of Ballygunge thana. The police say the robbers climbed up a scaffolding erected at the rear of the building for repairs and entered the apartment through a kitchen window, which the Guptas found broken.

“The apartment door was not broken and the main gate of the housing estate is manned by guards,” said Gyanwant Singh, the deputy commissioner of police (headquarters).

The domestic help of the Guptas, appointed a couple of months ago, is reportedly missing. “She was to come today to clean the apartment, but did not turn up. She might have tipped off the criminals,” said an officer working on the case.

“The robbers did not target any other apartment. They stopped at the window of the Guptas’ kitchen and broke the glasspanes,” said deputy commissioner Singh.

In the other incident, a 70-year-old woman was robbed by two youths in Tollygunge on Wednesday night.

Krishna Banerjee, 70, has been living alone in the second-floor flat on Nepal Bhattacharya Street since the death of her husband five years ago.

“The duo had pressed the doorbell and as soon as the woman opened the door, they pushed her aside and barged in,” said an officer of Tollygunge police station. They forced the woman to hand over the keys to the almirah, took out Rs 15,000 and fled. The police suspect local criminals were involved in the crime.