Prime Minister Anutin Charnvirakul has pledged to pursue long-term safety measures, including replacing railway crossings with tunnels or elevated routes, following Saturday's fatal collision between a freight train and a public bus at the Makkasan level crossing in Bangkok.

Speaking after visiting survivors at Camillian Hospital on Sunday, Mr Anutin, who also serves as interior minister, said authorities could no longer leave dangerous crossings unaddressed.

The crash at the Asok-Phetchaburi intersection near the Makkasan railway crossing left eight people dead and 32 injured after a freight train struck a Route 206 bus before the vehicle burst into flames.

The prime minister and officials visited patients at Camillian Hospital while pledging full assistance to victims and bereaved families.

He expressed condolences to the families of those killed and injured, calling the incident deeply tragic.

Police have filed charges against the train driver, while investigations continue into the actions of railway crossing staff and other officials involved.

Mr Anutin said video footage suggested the crossing barriers failed to lower because traffic congestion left vehicles stranded on the tracks.

He said trains had stopped on previous occasions when crossings were blocked, raising questions about why the train involved in Saturday's crash did not slow down or stop in time.

The State Railway of Thailand confirmed the crossing operated under a manual barrier system controlled by on-site personnel.

However, officials said the barriers could not descend because vehicles were on the crossing due to heavy congestion.

Under the rules, if train drivers do not receive confirmation that barriers are fully lowered, they must rely on visual signals from crossing staff.

Authorities are now examining data from the train's "black box" to determine whether proper procedures were followed.

Compensation for the families of those killed is expected to reach 1.5 million baht per victim, while injured passengers would receive between 80,000 and 500,000 baht depending on their injuries.

Local motorcycle taxi riders said accidents and collisions with crossing barriers occurred regularly at the junction because of chronic congestion and impatient driving.