TOKYO, May 12 (Reuters) - The Israeli foreign minister said on Wednesday that North Korean weapons seized in Thailand last year were headed for Islamist groups Hamas and Hezbollah.

More than 35 tonnes of arms including rockets and rocket-propelled grenades were seized from a cargo plane after it made an emergency landing at a Bangkok airport in December. Thai authorities said the plane came from North Korea.

In January, the Thai government sent a report to the U.N. Security Council stating the weapons were headed for Iran, which is allied to Syria.

With huge numbers of different weapons ... (it had the) intention to smuggling these weapons to Hamas and to Hezbollah, Israeli Foreign Minister Avigdor Lieberman told a news conference in Tokyo, where he is visiting until Thursday.

These cooperation between North Korea and Syria ... (do not) improve the economic situation in their countries, he said, speaking to reporters in English.

Israeli Deputy Prime Minister Moshe Yaalon said on Monday Israel was in a proxy war with Iran due to its sponsorship of Lebanon's Hezbollah guerrillas and the Palestinian Islamic movement Hamas.

Diplomats have said the movement of North Korean arms to Iran appears to have been an effort to violate UN sanctions against North Korea, diplomats said. Although Iran is subject to separate UN sanctions because of its nuclear program, it is not forbidden to import arms.

Pyongyang was hit with fresh UN sanctions last year to punish it for a nuclear test in May 2009, its second atomic detonation. The expanded measures are aimed at cutting off its arms sales, a vital export estimated to earn the destitute state more than $1 billion a year.

North Korea's biggest arm sales come from ballistic missiles, with Iran and other Middle Eastern states as customers, according to U.S. government officials. (Reporting by Yoko Kubota; Editing by Jeremy Laurence)