Sri Lanka deployed troops and police to distribute fuel on Wednesday as striking petroleum workers protested over plans to sell off stakes in state-owned oil depots to India and China.
The indefinite walkout by workers of the national oil company, backed by Sri Lanka's main leftist opposition party, is in response to the sale of state assets by the current government, which says foreign capital is needed to develop the island's infrastructure.
Constables and hundreds of troops were sent to man two main distribution points of the state-owned Ceylon Petroleum Corporation (CPC) near the capital Colombo, and have begun restoring supplies, police said.
"Petroleum distribution has been declared an essential service from midnight," said a government statement. "Those who do not report for duty today will be considered having vacated their posts."
"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 has 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, who downed tools on Tuesday, 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.
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 $1.12bn 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.