Major travel agencies and airlines in China are allowing clients with travel plans to Sri Lanka to postpone or cancel their trips in the wake of a series of blasts on Sunday that killed at least 290 people and injured more than 500.

Xinhua reported on Monday that one Chinese had been killed, five were missing and another five injured, citing the Chinese embassy in Sri Lanka.

China-based travel agencies have reported no casualties among their clients visiting Sri Lanka at the time of the explosions, and they have taken measures to keep Chinese visitors safe and are allowing others to change their itineraries.

Domestic tour operator Tuniu said customers with existing hotel bookings in Colombo, the Sri Lankan capital, on or before April 27 can cancel their bookings free of charge.

Colombo was hit hardest by the bombs, as seven explosions shattered hotels and churches in the city on Sunday and Monday. Two explosions occurred in neighboring Negombo and the eastern city of Batticaloa, according to Xinhua News Agency.

Other Chinese travel agencies, including Ctrip, Lvmama and Aoyou, have also rolled out similar policies to accommodate clients' needs to defer or cancel their booked trips due to the ongoing volatility of the situation in the island country.

Flights between the Chinese mainland and Sri Lanka operated by Air China, China Eastern Airlines and China Southern Airlines have not seen widespread delays or cancellations, according to Variflight, an aviation data provider.

The three largest air carriers in China are offering full waivers on cancellations and rescheduling requests for passengers who booked flights to or from Colombo before or on Sunday.

Sri Lanka Airlines confirmed that international flights were operating as scheduled at the Colombo airport. It also advised passengers to arrive at the airport at least four hours in advance with passports and valid tickets.

Tourism in Sri Lanka has seen a boom in recent years, with the number of Chinese tourists visiting the country more than doubling in the past four years, reaching about 270,000 last year, China News Service reported in February.