At least ten people are dead with more than 100 missing after a flyover, which was still under construction, collapsed in India's West Bengal state. The army has been deployed to oversee rescue operations.

The structure came down in a busy market area in northern Kolkata, the capital of West Bengal, at noon local time on 31 March. Witnesses from the area say as many as 150 people have been trapped under the debris. Several vehicles are also caught under mounds of rubble.

CCTV of Kolkata flyover collapsing IBTimes UK

The collapse site is located in a densely populated area known as BaraBazar, which is frequented by labourers and traders. Heavy duty cranes have been taken to the site to remove fallen girders and concrete.

West Bengal's chief minister, Mamata Banerjee, has cancelled a planned political rally and is on her way to the site as of press time. The cause of the collapse is not clear so far, although fingers have been pointed by rival politicians.

"Mamata's government is responsible for this. We want action to be initiated against the ministers and people associated," said Kailash Vijayvargiya, a senior leader of the Bharatiya Janata Party in West Bengal – where the state elections are only months away.

Federal Home Minister Rajnath Singh has confirmed assistance from the central government.