Chinese President Hu Jintao on Wednesday expressed his "deep condolences" over the death of a Chinese UN observer killed in an Israeli air raid on a UN post in south Lebanon, according to a statement from Chinese Foreign Ministry.

President Hu "demanded the Chinese departments concerned properly handle the aftermath of the incident and take every measure necessary to ensure the safety of Chinese nationals in Lebanon," said the statement.

The air raid on early Wednesday killed four UN observers, including one from China. The other three were from Finland, Austria and Canada, UN Interim Force in Lebanon (UNIFIL) sources confirmed.

"After being informed of the tragic death of the Chinese peacekeeper early this morning, President Hu had instructed the departments concerned to condemn the attack on UN peacekeepers and expressed his deep condolences on the victims and sincere sympathy for their families," it said.

The Chinese victim named Du Zhaoyu, a Lieutenant Colonel of the Chinese People's Liberation Army with a postgraduate degree, was born in Jinan, capital of east China's Shandong Province. He was sent to Lebanon in January this year as a UN observer.

Du had worked as secretary to the military attache in the Chinese embassy in India. Du is survived by his wife, who also serves in the Chinese military, and a one-year-old son.

China on Wednesday felt "deeply shocked" by and "strongly condemned" an Israeli air raid and urged for immediate ceasefire.

"China urges the concerned sides, especially Israel, to take tangible measures to ensure the security of UN peacekeepers," said Foreign Ministry spokesman Liu Jianchao Wednesday.

He called on concerned sides back to the track of talks to seek a political solution.

"China will work with the international community, further diplomatic efforts and push the Middle East situation back to peace and stability at an early date," Liu said.

Chinese Assistant Foreign Minister Zhai Jun called in Israeli Ambassador Yehoyada Haim Wednesday morning and made solemn representations.

"China strongly condemns the activity to raid the UN peacekeeping post and urges Israel to carry out a thorough investigation and apologize to China and the victim's families, and coordinate with China to deal with the aftermath," Zhao told the ambassador.

Israel has intensified its air raids on Lebanese targets since launching a massive assault on July 12 when Lebanon's Hezbollah guerillas kidnapped two Israeli soldiers and killed eight in cross-border attacks.

Over 350 Lebanese and 42 Israelis have been killed in the two-week conflicts.

Some 180 Chinese staff officers, engineers as well as three observers, including Du, were working in Lebanon, as part of the UN peacekeeping mission, according to diplomatic sources.

"Since the armed conflicts broke out in mid-July, President Hu has made quite a few instructions, requiring the related departments to ensure the safety of the Chinese people in Lebanon, " according to the statement.

Chinese Ambassador to the UN Wang Guangya on Wednesday made an emergency call to UN Deputy Secretary-General Mark Malloch Brown, asking the UN to require Israel to take every measure to ensure the safety of UN peacekeepers, including those from China, and look into the incident.

Milos Struger, spokesman of the UNIFIL said earlier that an Israeli bomb directly hit the base of the UN Observer Group in the town of Khiam near the eastern end of the border with Israel.

UN Secretary-General Kofi Annan said in a statement that he was "shocked and deeply distressed" by the attack, saying it's "apparently deliberate targeting by Israeli Defense Forces."

In Jerusalem, Israel expressed regret on Wednesday over the deaths of four UN observers in south Lebanon.

"Israel sincerely regrets the tragic death of the UN personnel in south Lebanon," said Israeli Foreign Ministry spokesman Mark Regev.