Thousands of people across Japan took part Thursday in a massive earthquake drill, the first of its kind since the March 11 quake and tsunami that devastated the nation's northeastern coast.

Police redirected traffic and pointed pedestrians to earthquake shelters, while other authorities checked for gas leaks and simulated air-sea rescues over Tokyo Bay.

Outgoing Prime Minister Naoto Kan personally participated in the drill, announcing the earthquake at a simulated press conference.

The drill is held every year on September 1, the anniversary of a 1923 earthquake that leveled much of Tokyo and Yokohama, killing an estimated 130,000 people.

This year's drill held special significance, coming less than six months after the March disasters which left more than 20,000 people dead or missing. A government statement urged citizens to prepare for every possible scenario and pay special attention to the risk of another tsunami.

As many as half a million people took part in the drill, and many said they found it a valuable exercise.

Ironically, the drill was canceled in many areas that were struck by the March disasters. Officials said residents there were still too busy struggling to recover from the real thing.