Several days after the start of spring, Scotland and Northern Ireland were battered by snow, gale force winds and torrential rain on Wednesday, leaving thousands of people without power and causing havoc on roads. Scottish police said a group of teenagers on a school trip were injured after their bus veered off a road and crashed into water near Biggar, 50 miles (80 kilometers) southwest of Glasgow. A police spokeswoman said four of the group of 39 people were seriously injured. Conditions in the area were described by police as «horrendous.» Britain's weather agency said the tough weather conditions will continue through Wednesday. High winds, snow in drifts up to 20 inches (50 centimeters) and blizzards are expected. The worst conditions are forecast for the Scottish highlands. This follows one of Britain's coldest winters in decades. Northern Ireland Electricity said nearly 50,000 customers lost power after damage to its network overnight. High winds and poor visibility stopped workers from climbing poles to fix the problem. More than 20,000 homes in Scotland were without power. A Scottish Power spokesman said 500 engineers _ and another 100 who came from England to help _ were working on the problem, but they were having difficulty reaching remote areas because the conditions were too difficult. Drivers were warned to stay off the roads for all but the most essential travel. Some train services were canceled. In Northern Ireland, emergency services had to rescue about 300 stranded travelers, whose vehicles were stuck in snow, from a highway near Londonderry, the province's second-largest city, according to a report of the Associated Press.