11.   On the other hand, sudden releases from ice jams that abruptly dislodge can send floodwaters rushing downstream.

12.   Sometimes, in northern areas, ice jams exacerbate the floods on swollen rivers.

13.   The flooding was caused by an ice jam, a common occurrence on northern rivers in the late winter and spring.

14.   There was relatively little scouring of the stream bottoms by ice jams and uprooted trees.

15.   But emergency workers using icebreakers and explosives were unable to destroy all the ice jams clogging the river and the rising waters still posed a threat to villages downstream.

16.   Demolition experts were brought in on four helicopters to dynamite the ice jam so that the river could start flowing normally again, the agency said.

17.   Demolition experts from the city of St. Petersburg were working to break up the ice jam by dropping explosives onto the ice from a plane, the report said.

18.   Emergency workers have battled the ice jams using jet bombers and icebreakers.

19.   Elsewhere in the Red River Valley, a state of emergency was declared at Crookston, Minn., where ice jams threatened flooding on the Red Lake River.

20.   Flood waters in the Yakutia region of eastern Siberia continued to recede Saturday following the destruction of an ice jam on the Lena River, a news agency reported.