Violence broke out on the border Friday for the first time in four months as preparations quickened for Lebanese parliamentary elections in two weeks’ time.

The flare-up underlined the dangers of a power vacuum in Lebanon after Syria ended its 29-year troop deployment last month.

An Israeli military spokeswoman reported no fewer than nine explosions near Israeli positions in the disputed Shebaa Farms district.

Israeli tanks, artillery and warplanes retaliated, destroying four Hezbollah positions across the border, she added.

Lebanese police said Israeli gunners began the clashes with heavy machine-gun fire on the village of Kfarshouba early afternoon, which damaged a house but caused no casualties.

Israel denied the Kfarshouba shooting.

Hezbollah said it retaliated by firing two shells on Rweissat al-Alam, an Israeli position in the Shebaa Farms.

Israeli jetfighters launched two successive retaliatory raids while helicopter gunships, tanks and artillery pounded nearby border areas, police said.

There were no immediate reports of casualties.

UN Secretary General Kofi Annan called on “all parties to exercise the utmost restraint in a situation that continues to be fragile, not just in Lebanon but also in the wider region,” his spokesman said.

“The secretary general once again urges all parties to fully respect the Blue Line (border), which was unanimously determined by the Security Council, and reminds them that one violation cannot justify another,” he said.

In Washington, State Department spokesman Richard Boucher said the “United States is deeply concerned about the recent violence along the Blue Line.

“We call on all parties to immediately cease all attacks and to exercise calm and restraint.

“This is an especially sensitive and critical time for the Lebanese people, who will be voting in parliamentary elections beginning on May 29,” Boucher said.

“This opportunity for reaffirming democracy in Lebanon must not be undermined by militias pursuing their own agendas.

“All militias in Lebanon, including Hezbollah, must disarm and disband, and the Lebanese government must extend and exercise its sole and exclusive control over all of Lebanese territory,” Boucher said.

Resolution 1559, passed by the UN Security Council last September, demanded the disarming of all militia groups in Lebanon.

The retaliatory raids were the first since air attacks on January 17 wounded two Lebanese civilians, reviving the lingering tension that has prevailed in the region since Israel ended its 22-year occupation of southern Lebanon in 2000.

Foreign Minister Mahmud Hammud blamed Israel for the rising tension and urged the “international community and the United Nations to act to secure regional stability.”

Prime Minister Nagib Miqati contacted the UN peacekeeping force in south Lebanon in a bid to “ease tensions”, the official ANI news agency said.

Tension had been rising for several days, exacerbated by two blasts in 24 hours on the Israeli side that prompted stern warnings from Israel that it held the Lebanese government responsible for maintaining peace in the area.

“Israel holds Lebanon responsible for what happens on its border,” said Defence Minister Shaul Mofaz.

“We are following events in Lebanon closely. The Syrians continue to play a certain role despite announcing their troops have withdrawn.””

Syrian troops and intelligence agents pulled out less than three weeks ago in a withdrawal that is being verified by the United Nations.

The Syrian-backed Shiite militant group Hezbollah, which had 12 MPs in Lebanon’s outgoing parliament, controls virtually all the area along the border and has vowed to liberate the Shebaa Farms.

Seized from Syria in the 1967 Arab-Israeli war along with the rest of the Golan Heights, the territory is now claimed by Lebanon with Syrian blessing although Israel rejects the arrangement.