In pictures: rescue efforts under way as India buildings collapse

Rescuers at the site of the collapsed building. Anindito Mukherjee/Reuters

The four-storey building in New Delhi was in an area inhabitaed by the poor. EPA

Eleven people died and one survivor was being treated in a hospital, said fire service officer Praveer Haldiar. EPA

Most homes in that part of the capital were built without permission and using substandard materials, said police officer Madhur Verma. Anindito Mukherjee/Reuters

The Press Trust of India news agency said the New Delhi collapse was triggered by construction work on an adjacent plot. Anindito Mukherjee/Reuters

Another building, a 12-storey structure that was under construction, also collapsed on Saturday, following heavy rains and lightning in the outskirts of Chennai, the capital of Tamil Nadu state. Babu/Reuters

Eleven people were killed in the second collapse but rescuers are still searching for others who may be trapped in the rubble. Babu/Reuters

Building collapses are common in India, where high demand for housing and lax regulations have encouraged some builders to cut corners, use substandard materials or add unauthorised extra floors. Anindito Mukherjee/Reuters

Two separate buildings collapse in India over the weekend. The first was a 50-year-old structure in New Delhi that toppled early Saturday, killing eleven people. The second took place in the outskirts of Chennai – the capital of Tamil Nadu. At least eleven people were killed, and more than a dozen injured.