Prime Minister Narendra Modi on Thursday took stock of the situation in Andhra Pradesh's Visakhapatnam where a gas leak from a chemical plant has left 11 dead, and assured all possible assistance to state Chief Minister Y S Jagan Mohan Reddy.

The prime minister also chaired a meeting of the National Disaster Management Authority (NDMA) to assess the situation.

The prime minister wrote on Twitter that he spoke with officials of the Union Home Ministry and NDMA regarding the situation 'which is being monitored closely'.

'I pray for everyone's safety and well-being in Visakhapatnam,' he said.

The Prime Minister's Office said Modi spoke to the state chief minister.

'He assured all help and support,' a PMO tweet said.

After the meeting of NDMA chaired by Modi, his principal secretary P K Mishra reviewed the situation with top government officials.

In the review meeting with cabinet secretary, home secretary, NDMA, National Disaster Response Force, director All India Institute of Medical Sciences, and medical experts, Mishra directed that team of experts be sent to the spot.

He also directed that short term as also long term medical impact of the gas leak be looked into, sources said.

At least 11 people have died and several hospitalised after a gas leak at a chemical plant in Visakhapatnam in the early hours of Thursday.