HANOI, May 13 (Xinhua) -- A cargo train was derailed on Monday morning in Vietnam's northern Nam Dinh province, causing no casualties but paralyzing the country's north-south railway for several hours, local media reported.

Several compartments of the HH4 train derailed in My Loc district, which damaged some 600 meters of rails, Vietnam News Agency reported.

Since the beginning of this year, Vietnam has seen six cases of trail derailment, each of which paralyzed the north-south railway for hours, online newspaper VnExpress reported on Monday.

Old compartments, uneven quality of compartments and poor maintenance of rail infrastructure could have led to the derailments, VnExpress quoted Vu Quang Khoi, head of the Vietnam Railway Authority, as saying.

The state-owned Vietnam Railways Corporation has recently installed surveillance cameras at locomotives of trains to timely give warnings when they approach rail sections which cross roads.

Vietnam's railway sector transported 2.6 million passengers in the first four months of this year, seeing a year-on-year drop of 9.3 percent, and 7.7 million tons of cargoes, down 12.9 percent, according to the General Statistics Office.