The Foreign, Commonwealth and Development Office advises against all but essential travel.
The Indian Ocean destination has ongoing political and economic instability that has strengthened the warning.
An island-wide curfew is in place after a state of emergency was declared.
Several incidents took place on 9 May involving violence against peaceful protesters, including in the Galle Face area in Colombo, where the security authorities used tear gas and water cannons.
There were injuries and loss of life due to incidents near Beira Lake in the country. There could be more incidents.
If you're planning to travel to Sri Lanka at this time, you should follow the advice of local authorities.
International travellers can use their passports and airline tickets as curfew passes to travel to and from the airport.
Protesters were calling for the resignation of the president over the economic crisis.
The prime minister, his brother, stepped down on Monday.
There is a travel alert for Sri Lanka.
The FCDO advised that the economic situation is getting worse with shortages of basic necessities.
There may be long lines at shops and supermarkets. There are daily power cuts due to rationing.
There have been a number of protests. There are likely to be more protests across the island.
Local restrictions may be imposed by the Government of Sri Lanka. You should follow the advice of the local authorities, avoid large gatherings, and be vigilant.
The advice against all but essential travel does not apply to airside transit through the international airport.