DAKAR, Aug 6 (Reuters) - Congolese health authorities were screening more than 300 people travelling on a river boat intercepted near Kinshasa on Thursday after the death of a passenger suspected of having Ebola raised concerns the virus may have spread on board, officials said.

Authorities deployed a mobile laboratory to the vessel after it was stopped in Maluku, around 65 km (40 miles) upstream from the capital on Wednesday.

The secretary-general of Congo's health ministry, Body Ilonga Bompoko, said all passengers were undergoing temperature checks and clinical screening.

He told reporters samples had been collected from four passengers with symptoms including fever and sent for testing, with results expected on Friday.

The operation was launched after health authorities in Mongala province reported the death on July 25 of a 32-year-old man suspected of having Ebola who was believed to have travelled on the vessel.

Officials have given differing accounts of the man's movements and where he may have contracted the virus.

Africa CDC Director General Jean Kaseya told reporters on Thursday the boat came from Mongala province, where no Ebola cases have been recorded, rather than from Tshopo province, where the outbreak has spread. Congolese authorities had earlier identified Kisangani, the capital of Tshopo, as the vessel's point of origin.

Mongala provincial health chief Eustache Bibala Faray said authorities had not established where the man boarded the vessel. Health officials initially linked him to Kisangani because documents found on him indicated he was from there, he told Reuters.

VACCINES, TREATMENTS TO BE EXPANDED

Separately, Kaseya said authorities had decided to expand use of a vaccine developed against the Zaire ebolavirus species after data suggested it provided some protection against the Bundibugyo species driving the current outbreak.

(Reporting by Clement Bonnerot and Benoit Nyemba; additional reporting by Anait Miridzhanian; editing by Jessica Donati and Mark Potter)