South Korean conservative activists hold a portrait of North Korean leader Kim Jong Il during a rally Tuesday denouncing North Korea's missile test in Seoul, South Korea. (Lee Jin-man/Associated Press)

North Korea appears to be preparing to fire more missiles, news reports said Tuesday in Seoul — a day after the country launched five short-range ballistic missiles into its eastern waters.

Citing an unidentified government official, both the Yonhap news agency and the YTN television network reported that North Korea had announced a no-sail zone in areas off the country's east and west coasts for Oct. 10 to 20 — an apparent signal it would carry out more missile tests.

The move comes ahead of possible talks with the United States. Washington has said it is considering holding direct talks with North Korea to restart the six-party negotiations, which also include South Korea, Japan, China and Russia.

Monday's launches appeared to be aimed at displaying North Korea's missile capability to bolster its negotiating hand ahead of talks with the U.S. and other countries to wrest more concessions, said Koh Yu-hwan, a North Korea expert at Seoul's Dongguk University.

U.S. Secretary of State Hillary Rodham Clinton is in Moscow to meet with Russian leaders on a variety of issues, including nuclear reduction concerns.

She said American efforts to resume nuclear talks with North Korea will proceed despite the new tests.

Meanwhile, about 200 demonstrators gathered in central Seoul on Tuesday to denounce the North's missile launches with some burning North Korean flags and photos of North Korean leader Kim Jong Il.