The indefinite strike by workers of Sri Lanka's state oil company has triggered fears of a fuel crisis, with long queues building up outside petrol stations across the country

Sri Lanka arrested dozens of striking oil workers Wednesday as the military moved in to restore supplies and end fuel shortages, officials said.

Police said they arrested 20 workers of the state Ceylon Petroleum Corporation (CPC) who defied an order by President Maithripala Sirisena on Tuesday banning strikes in the energy sector.

The military said it deployed armed troops to guard two wholesale oil distribution depots and ensure gasoline and diesel were distributed.

Prime Minister Ranil Wickremesinghe told parliament that a tanker train carrying aviation fuel was also despatched to the airport despite attempts by strikers to block it.

Hundreds of workers have been on strike since Tuesday night, protesting government plans to sell off stakes in state-owned oil storage depots to India and China.

The indefinite walkout by CPC workers was instigated by former president Mahinda Rajapakse, government spokesman Rajitha Senaratne told reporters in Colombo.

"It is the Rajapakse faction that is behind the strike," said Senaratne. "They think they can bring the government down through this action, but we will not allow that."

"The army has assisted the police in providing security to two oil distribution centres," military spokesman Roshan Seneviratne told AFP. "We also provide security to those who have reported for work to restore supplies."

The strike triggered fears of a fuel crisis on the island, with long queues of cars and trucks building up outside petrol stations across the country during the night.

CPC trade unions said they will not return to work until the government abandons plans to sell stakes in oil storage tank facilities in the northeast and south of the island.

Sri Lankan authorities want to form a partnership with a Chinese company to develop the loss-making Hambantota port

The government has said it wants to develop a disused World War II-era oil depot in the northeastern port of Trincomalee with an Indian state-owned company.

Authorities also want to form a partnership with a Chinese company to develop the loss-making Hambantota port, including its oil storage tanks, in the island's south.

The government finalised a $1.12 billion deal to sell off a majority stake in the strategically sited port to Beijing's state-owned China Merchants Port Holdings on Tuesday. The deal is to be signed on Saturday.