After a month punctuated by terrorist attacks, Tokyo is beginning to look like a city under siege.
Commuters used to be reminded not to forget their umbrellas on trains. Now they're warned, "Don't touch any suspicious parcels. They could be poison." The signs of the times are everywhere in train and subway stations, where 12 people were killed and 5,500 injured in a nerve-gas attack a month ago and another 500 were sickened by a less toxic gas attack in Yokohama on Wednesday.Coin lockers are sealed in the stations. Many vending machines have been unplugged. Garbage cans have been removed or sealed. Passengers are urged to be on the lookout for suspicious people, boxes or bottles.
A general feeling of anxiety is making itself felt elsewhere as well.
Drivers are learning to live with random checks on major roads. Riot police in full battle gear are a common sight on strategically located street corners.
Even the airwaves seem to be heating up.
"Here it comes," said taxi driver Suero Oku as police broke into his cab's radio frequency Thursday to make an emergency announcement. Oku said police have recently made frequent radio requests for cabbies to be on the alert for suspicious characters.
"Japan has never seen anything like this before. Even the Red Army was nothing compared to now," he said, referring to an ultraleftist group involved in hijackings and several terrorist attacks in the 1960s and '70s.
For many Japanese, the most disconcerting aspect of the violence is that two of three attacks over the past month were clearly intended to kill, rather than to frighten or highlight a political cause.
Equally alarming is the lack of any claim of responsibility for the attacks, despite the largest criminal investigation in Japanese history.
The main suspect in the March 20 Tokyo attack is an apocalyptic religious cult. The cult has denied involvement, but there are almost daily reports of police finding dangerous chemicals, gun parts or ingredients that could be used to concoct biological weapons at cult facilities around the country.
Ten days after that attack, the national police chief heading the investigation barely survived an assassination attempt.
When news reports last weekend warned of a possible attack by cult members, 10,000 police were mobilized to prevent any trouble. Many in Tokyo stayed home for fear something would happen, but the weekend passed without incident.
As a parliamentary committee met Thursday to discuss the recent violence, police scrambled to identify the gas used in Yokohama, a city of 3.3 million people just south of Tokyo.