Workers blew up a frozen river to prevent an ice jam in northern China.

The video, filmed in the county of Yilan in Heilongjiang Province on March 22, shows water being blasted dozens of metres into the air after explosives inside the frozen river were detonated.

According to reports, 120 holes were dug out on the frozen Songhua River and 1,800-kilogram explosives were used to blow the icy river up.

When the upstream of the river starts to melt, the big chunks of ice flowing downstream may form ice dams. If the ice dams break, the ice chunks would crash into the buildings on two sides of the river and affecting residents' safety.

The video was provided by local media with permission.

22日11时20分许，随着爆破组长下达指令，一声声爆破声接连响起，松花江干流依兰段冰封的江面上升起一朵朵“冰雪烟花”，短短几分钟，总长1800米的防凌爆破顺利完成。这是省水利厅对容易出现凌汛的松花江干流依兰段进行主动爆破，也是松花江干流依兰段近20年首次防凌爆破。
据省水利厅有关负责人介绍，由于去年冬季和今年春季全省降水量较大，经过相关部门预测，开江期松花江干流中下游发生一般性冰坝可能性较大，容易影响到两岸居民和耕地安全。为此，省水利厅在松花江干流依兰段的两处江段开凿了120个爆破孔，使用了1800公斤的炸药，通过防凌爆破方式人为松动冰封的江面，防止上游的冰块堆积形成冰坝。
该负责人表示，所谓冰坝是由于江面上游解冻时，顺流而下的大量冰块受阻于封冻的下游江面，形成一个冰块堆成的堤坝。当冰坝承受不住上游江段冰块和江水的压力时会自然溃决，大量流冰突然下泄，撞击沿江两岸建筑物，影响到江边两岸居民和耕地安全。（视频由黑龙江台提供）