Thousands of people have taken to the streets across Sri Lanka a day after police opened fire at demonstrators, killing one person and injuring 13 others, reigniting widespread protests amid the country's worst economic crisis in decades.

Protesters used vehicles to block key roads in many parts of the country as they demonstrated against the shooting as well as rising fuel prices and the government's failure to resolve the deepening economic problems.

The shooting was the first by Sri Lankan security forces during weeks of protests.

The shooting occurred on Tuesday in Rambukkana, 55 miles north east of Colombo, the capital. Fifteen police officers were also admitted to hospital with minor injuries after clashes with protesters.

Police said the demonstrators had blocked railway tracks and roads and ignored police warnings to disperse. Officers also said protesters threw rocks at them.

On Wednesday, thousands of bank, port, health and other state employees demonstrated in front of the main railway station in Colombo, condemning the police shooting and demanding that President Gotabaya Rajapaksa resign.

Sri Lanka is on the brink of bankruptcy, with nearly 7 billion dollars (£5.4 billion) of its total 25 billion dollars (£19 billion) in foreign debt due for repayment this year. A severe shortage of foreign exchange means the country lacks money to buy imported goods.

US ambassador Julie Chung and UN official Hanaa Singer-Hamdy urged restraint from all sides and called on the authorities to ensure the people's right to peaceful protest.

Ms Chung also called for an independent investigation into the shooting.

Sri Lankans have endured months of shortages of essentials such as food, cooking gas, fuel and medicine, lining up for hours to buy limited stocks.

Fuel prices have risen several times in recent months, resulting in sharp increases in transport costs and prices of other essentials. There was another round of increases earlier this week.

Thousands of protesters continued to occupy the entrance to the president's office for a 12th day on Wednesday, blaming him for the economic crisis.

Prime Minister Mahinda Rajapaksa said on Tuesday that the constitution will be changed to curb presidential powers and empower parliament, amid growing protests demanding that the president and his powerful family resign.

He said the power shift is a quick step that can be taken to politically stabilise the country and help talks with the International Monetary Fund over an economic recovery plan.

President Rajapaksa, the prime minister's brother, concentrated power in the presidency after being elected in 2019.

The brothers are likely to retain their grip on power even if the constitution is amended, since they hold both offices.

Both men have refused to step down, resulting in a political impasse. Opposition parties have rejected the president's proposal of a unity government but have been unable to put together a majority in parliament and form a new government.

In a cabinet reshuffle on Monday, the president appointed many new faces and left out four family members who had held cabinet and non-cabinet posts, in an apparent attempt to please the protesters without giving up his family's grip on power.