A highway pileup in China's island province of Hainan has killed three people and injured one, sources with the local police said.

The deadly accident happened around 7:45 a.m. Saturday on a highway west of Changjiang County in northwestern Hainan, when a speeding car crashed into a truck that stopped there with a flat tire, police said.

The truck veered towards the insulation belt between the lanes and hit another brick-laden truck.

Ten firefighters were sent for the rescue work. Three passengers on the car died on the scene. Another passenger was seriously injured and has been sent to a local hospital.

The highway resumed operation after being sealed off for two hours.

Road accidents killed 37,000 people and left another 189,000 injured in the first half of the year, causing direct losses of 540 million yuan (71 million U.S. dollars), according to latest figures released by the traffic management department under the Ministry of Public Security.

Overloading, speeding and fatigue driving are identified as the three major causes of road accidents.

China has enforced tougher driving test regulations since April to improve the drivers' safety awareness.

The new regulations require learners to pass at least 10 out of 13 practical tests, which include changing lanes, traversing intersections and night driving.

Applicants will also be tested on real roads with a single-way traffic flow of at least 60 cars per hour. Learners in mountainous areas will take additional tests on roads with tunnels, culverts and steep slopes, according to the new regulations.