Baby babble brings bad vibe in Japan

The US military is in trouble in Japan -- but this time it's not low-flying fighter jets or misbehaving Marines who are ruffling feathers, but infant babble transmitted over illicit baby monitors.

Japan's Internal Affairs and Communications Ministry has warned the 47,000 US forces based in the country that the devices used by service personnel with young children interfere with local radio frequencies.

Some US-bought baby monitors transmit signals on wavelengths that are reserved for cellphone traffic and radio services in Japan, and are strong enough to cause interference, a ministry official told AFP.

"Our ministry is asking the US military for permission to visit the families who are illegally emitting these frequencies and personally ask them to avoid using the baby monitors," the official said.

The radio transmitters, which allow parents to check on an infant in a different room, have also interfered with the radio services of taxi and truck companies and threaten firefighters' communications, media reports said.

The US armed forces have faced controversy in the past in Japan -- including a recent row over a noisy airbase on the southern island of Okinawa, and because of past misdemeanours and crimes committed by troops.

But the US military vowed the baby monitors must not get in the way of relations with its Asian security ally.

A spokeswoman told AFP that the US Forces in Japan had banned the sale of the devices on base and "taken proactive measures to educate the US military community ... in Japan that US-purchased baby monitors can affect Japanese frequencies and should not be used here in Japan."