Japan’s Foreign Ministry said Monday that travelers should be cautious when using public transportation and visiting tourist sites.
On Sunday, Britain warned its citizens of a “high” threat of terrorism in France and Germany.
The U.S. State Department has also issued an alert, cautioning Americans of possible terrorist attacks in Europe by al-Qaida and its affiliates.
Western intelligence officials said last week they had uncovered a plot by al-Qaida-linked militants based in Pakistan for terror attacks in major British, French and German cities.
Officials say the plot is believed to involve multiple attacks on public places – similar to those carried out in Mumbai, India in 2008, when near-simultaneous attacks by Islamic militants killed or wounded nearly 500 people.
The State Department is reminding U.S. citizens of the potential for terror attacks on public transportation systems and other places frequented by tourists. U.S. officials urged American travelers to be vigilant and aware of their surroundings.
The alert is below the level of urgency of a travel “warning,” which could lead Americans to cancel holidays and other trips to Europe.
Intelligence officials say some recent missile attacks against militants in Pakistan’s northwestern tribal region were aimed at thwarting the plot.