Preparations for two PAC-3 launchers at the Self Defense Forces' Narashino base, just east of Tokyo, began Thursday, said an official at the Defense Ministry, speaking on condition of anonymity because of policy.
Kyodo News agency said the two launchers were installed early Thursday, but the official refused to confirm that, citing security concerns.
The deployment will be completed by the end of January, she said.
It will be the second deployment of the PAC-3 defense system in the Tokyo area. The first was at the Iruma base in March. There are two launchers there as well, the official said.
Japan, concerned by possible threats from North Korea, plans to deploy the PAC-3 defense system at nine more bases by March 2011.
The expanded deployment comes as Japan is rapidly strengthening its defenses.
The Defense Ministry is reportedly planning to conduct anti-ballistic missile drills in the Tokyo area beginning next month, setting up PAC-3 systems at about 10 locations throughout the city.
The drills are aimed at testing the locations to see if there are any communications obstacles in the surrounding areas and determine the best locations for future deployment, the Yomiuri newspaper reported.
Officials at the Defense Ministry confirmed that they intend to conduct drills, but refused to give any details.
In March, a pair of PAC-3 launchers was installed at the Iruma base, about 40 kilometers (25 miles) northwest of Tokyo. But to defend the capital against a possible attack, the missiles - which have a range of 15-20 kilometers (9-12 miles) - would have to be brought into Tokyo.
The ministry plans to conduct similar drills in the central, western and southwestern regions later, the Yomiuri said.
The Patriot surface-to-air missiles would be used as a last resort if interceptors fired from U.S. or Japanese ships fail to knock out incoming missiles.
Japan will begin introducing Standard Missile-3 interceptors on its destroyers over the next few years as part of that effort. It plans to conduct its first missile test in mid-December from an Aegis-radar equipped destroyer off Hawaii.
In February, the U.S. military deployed a detachment of Patriot missiles at a base on the southern Japanese island of Okinawa, where most of the roughly 50,000 American troops in the country are based. Pravda.ru