As some 500,000 vehicles carrying Athenians on their way back from Easter celebrations in the countryside returned to the capital yesterday, traffic police said 18 people had died in as many crashes over the last five days. The accidents, however, did not occur on the busy national road network but in built-up areas and mostly on country roads, police said. They gave no details of the number of people injured in the crashes. Over 800,000 cars left Athens during Holy Week, in what authorities described as the biggest mass departure to take place in the last five years. Of these, some 300,000 vehicles are expected to return to the city over the course of this week. In anticipation of the increased traffic, more than 2,600 traffic police officers were patrolling national roads, clamping down on drunk driving in particular. They conducted almost 10,000 alcohol tests on drivers during Holy Week and found 189 drivers to be over the legal limit. In 20 cases, the vehicles were impounded on the spot and the drivers were taken to court.