TOKYO (Reuters) - Japan tightened security on Friday at 650 vital facilities around the country, including nuclear power plants, government offices and U.S. facilities, to guard against a possible terrorist attack, a National Police Agency official said.The official said the heightened alert was due to such factors as Japan's recent dispatch of a main contingent of ground forces to help rebuild Iraq.
But he declined to say whether there had been any fresh information concerning a possible attack.
There were two late-night explosions near the Defense Ministry in Tokyo this week, which police said could have been carried out in a protest against the dispatch of Japanese troops to Iraq.
The dollar rose sharply against the yen in late afternoon trade in Europe following the report that Japan's security level had been raised.
The National Police Agency said in December that Japan's close ties with the United States and the many U.S. facilities in the country could make it a target for attacks by Islamic militants.
Japan approved the controversial dispatch of its main army contingent to help rebuild Iraq in late January, and now has some 100 troops establishing a base in Samawa in southern Iraq, where they will help with humanitarian work and reconstruction.
Nudged by the United States, Japan plans to send up to 600 ground troops to Iraq as part of a total deployment of around 1,000 military personnel. It will be Japan's biggest and riskiest overseas mission since World War II.
Japan is one of the United States' closest allies in Asia and is host to about half the approximately 100,000 U.S. military personnel in the region. Many U.S. companies have a substantial presence in the country.
No damage or injuries were caused by Tuesday's explosions.
A leftist group calling itself "Kakumeigun" (Revolutionary Army) has sent letters to Japanese media claiming responsibility, Kyodo news agency said on Friday. The group said it was resorting to violence to prevent the deployment of Japanese troops to Iraq, Kyodo said.
