TOKYO (AFP) - Nationalist groups rallied in Japan on Saturday against the country's "diplomatic defeat" to China in a maritime dispute, amid growing Russian pressure over another simmering territorial row.

Japanese national flags fluttered in Tokyo's Yoyogi park where organisers said some 1,500 people had gathered, with many holding banners reading: "Never tolerate weak Kan government defeated to Chinese threats".

The rally was organised by a nationalist network chaired by former air force chief Toshio Tamogami, who was fired in October 2008 for penning an essay calling for the nation to shed elements of its post-World War II pacifism.

"China is claiming its sovereignty of the Senkaku and even eyeing at getting (southern) Okinawa main island under its control," said Tamogami in his statement. "The time has come for us to bolster our defence."

Following the rally, the anti-China protesters marched through Tokyo's fashionable Shibuya district, chanting: "Brave Japanese will fight! Proud Japanese will fight!"

They accuse China of an "invasion of the Senkaku" -- the Japanese name for disputed islands in the East China Sea, known as Diaoyu in China -- and are angry at Beijing's perceived hardline response to a diplomatic spat.

"Japan became numb because the peaceful time lasted too long," said Hiromitsu Yanashima, 31, hoisting a rising-sun flag. "We need to realise that China is thrusting a knife point at us."

Asia's two largest economies have been involved in a tense standoff since Japan arrested a Chinese trawler captain near the disputed islands on September 8.

Japan has since released the captain, but the move did little to ease tensions and left Kan open to domestic attacks from political conservatives claiming he had caved in to Chinese bullying.

As the row with China simmers, the centre-left Kan is facing another diplomatic challenge with Russian President Dmitry Medvedev expected to visit the disputed Kuril Islands.

The islands, which lie north of Japan's Hokkaido island, have been controlled by Moscow since they were seized by Soviet troops at the end of World War II but Tokyo still claims the southernmost four islands as Japanese territory.

The row has prevented Russia and Japan from signing a peace treaty to formally end World War II.

"I think Russia is taking passage in Japan's weak diplomacy," Yanashima said.

But some onlookers of the rally said they felt uneasy about the heated argument of the protesters.

"Before saying we are proud Japanese, we should be proud individuals. I feel rallying under such slogans may lead us to a war again," said teacher Yasuko Hirano.

China reacted strongly to the Senkaku dispute, freezing high-level talks and visits and taking punitive economic measures, according to industry sources, such as temporarily halting rare earth exports to Japan.

The damaging row, which has so far lasted more than three weeks, appears to have some way left to run, with Tokyo and Beijing continuing to trade calls for the other side to come to heel.

Beijing has issued a travel warning, cautioning its citizens over visiting Japan after right-wing nationalists harassed a group of Chinese tourists this week, surrounding and kicking their bus and hurling abuse.

China last month detained four Japanese construction workers for filming at a restricted military site before allowing three of them to return home Friday. One man remains in custody for further questioning.

On the Russian issue, Japan has already warned that a visit by Medvedev to the Kuril Islands would seriously hurt ties after he said he planned to travel to the islands while on a trip to the Far East this week and was only prevented by bad weather.