TOKYO -- Japan is bolstering security measures in response to the attacks in Brussels to ensure the safety of its citizens and to prevent a terror attack on its own soil, with a particular emphasis on key facilities such as airports and nuclear plants.

"We must be even more vigilant in preventing terrorism, by keeping our citizens abroad safe and enacting thorough security measures at home," Prime Minister Shinzo Abe said Wednesday.

The Ministry of Land, Infrastructure, Transport and Tourism called on travel agencies to notify Japanese tourists abroad of any travel warnings issued by the Foreign Ministry, as well as to make every effort to ensure their safety. It also warned airports and airlines of the possibility of a domestic terror strike, and advised the Japan Coast Guard to beef up surveillance around nuclear power plants by the sea.

The Ministry of Justice began obtaining the names and flight information of individuals seeking entry into Japan ahead of time from airlines around the world. It will turn back passengers from these lists if their names come up in terrorist databases.

The National Police Agency told its regional headquarters to beef up security at international airports, government offices and other key facilities. It urged for closer ties with restaurants, stadiums and other soft targets with less stringent security, and encouraged them to report any potential threats.

More than 20,000 police officers will secure the site of the Group of Seven summit in Mie Prefecture in May. "The summit, which will be attended by European leaders, has become an even tougher situation," a police official said.

(Nikkei)