The first five of a batch of French Rafale fighter jets purchased by New Delhi in a controversial  multibillion-dollar deal headed to India on Monday for rapid deployment amid rising tensions with China.

The deal, estimated to be worth $9.4 billion, has been shadowed by corruption allegations levelled by the opposition Congress party, though Prime Minister Narendra Modi has rejected the claims. The jets built by Dassault Aviation -- piloted by officers from the Indian Air Force (IAF) -- took off from Merignac in southwest France, the company said in a statement.

By Wednesday, the five planes should be at the Ambala air base in northern India, some 200 kilometres from the Pakistani and Chinese borders. They will refuel midair several times on the way and also make a stopover in Al Dhafra in the United Arab Emirates, where France has an air base.

Delivery of the Rafale jets -- 36 of which were ordered by India in September 2016 -- officially began in October but the planes stayed in France for training of the pilots and mechanics.

The delivery should be completed by 2022. "I am strongly impressed by the amazing efficiency and determination of the Indian Air Force and Indian Ministry of Defence," the chief executive of Dassault Aviation, Eric Trappier, said in a statement.

He said that despite the COVID-19 pandemic, they had managed to "master rapidly all aspects of the Rafale for comforting Indian sovereignty and contributing to the protection and security of Indian people."

The planes are awaited with impatience by New Delhi, which is eager to update its ageing fighter jet force as tensions flare with both China and Pakistan. Brutal hand-to-hand fighting in the Galwan Valley in Ladakh last month left 20 Indian soldiers dead. China has said it also suffered casualties but has not given figures.

Tensions are also running high with Islamabad after India scrapped the semi-autonomous status for the Muslim-majority region of Kashmir and imposed a major security clampdown. The IAF has said that once the planes arrive in India "efforts will focus on operationalisation of the aircraft at the earliest."