An Israeli police office guide Israeli civilians to evacuate from the scene where a building burns after a Katyusha-style rocket slammed into the building in the northern coastal town of Nahariya. Israeli forces intensified their retaliatory attacks in Lebanon Thursday and brought the death toll to 55 civilians. -Xinhua/AFP

Israeli forces intensified reprisal attacks on Lebanon on Thursday killing more than 50 civilians, as the international community pleaded for restraint from all parties in the crisis.

The Israeli army is imposing a comprehensive blockade on Lebanese air, sea and land in response to militia group Hezbollah's capture of two Israeli soldiers on Wednesday morning.

A total of 55 Lebanese civilians, including children, were killed in Israeli raids across the country, Hezbollah's television channel al-Manar reported.

On Thursday morning, Israeli aircraft bombed runways at Rafik Hariri International Airport, Lebanon's only international airport, forcing flights to divert to Cyprus.

Later in the day, Israeli aircraft attacked two Lebanese air force bases, and gunboats fired shells at fuel tanks at Beirut airport, witnesses said.

Al-Manar television station in Hezbollah's stronghold in Beirut's southern suburb was also hit by an Israeli missile, injuring six people.

Meanwhile, Israeli planes dropped leaflets in a Beirut suburb, urging residents to stay away from Hezbollah offices, witnesses said.

In order to retaliate for Israeli "massacres," Hezbollah fired around 60 Katyusha rockets at Nahariya in northern Israel, killing a civilian and wounding 21 others, al-Manar reported.

Israeli security sources said two Katyusha rockets fired from Lebanon also hit Israel's third largest city of Haifa on Thursday evening, while Hezbollah denied carrying out the attack.

Earlier, another rocket hit the northern Israeli city of Safed. One woman was killed and 20 others were wounded, the sources said.

The deterioration of the situation has sparked concerns around the world.

The United Nations Security Council is to hold an emergency meeting on Friday to discuss the dangerous situation along the Lebanese-Israeli border area.

UN Secretary-General Kofi Annan is sending a three-person team to the Middle East to try to defuse the crisis.

The International Committee of the Red Cross (ICRC) said it was gravely concerned about the plight of civilians caught up in hostilities in Lebanon and Israel.

"The ICRC is following the military developments in Lebanon and northern Israel with great concern, as these events are having a serious impact on civilians," the Geneva-based humanitarian agency said in a statement.

U.S. President George W. Bush, on a brief stopover to Germany's northern port city of Stralsund en route to Russia for the Group of Eight (G8) summit, accused Hezbollah of jeopardizing peace in the Middle East.

Israel has a right to defend itself, he told reporters in a joint press conference with German Chancellor Angela Merkel.

"My attitude is this: there are a group of terrorists who want to stop the advance of peace," Bush said, warning that any action taken must not weaken the democratic government in Lebanon, which he described as "very important" for peace in the region.

Finland, current holder of the European Union (EU) presidency, expressed great concern over the "disproportionate" use of force by Israel in Lebanon.

In a statement, the EU presidency deplored the loss of civilian lives and the destruction of civilian infrastructure, saying the imposition of an air and sea blockade on Lebanon cannot be justified.

The EU presidency urged all countries in the region to work for the restoration of calm in order to avoid a further deterioration of the situation into war.

In London, British Foreign Secretary Margaret Beckett urged all parties in the Middle East region to exert restraint in the current violence.

After talks with EU foreign policy chief Javier Solana, Beckett said she and Solana "are gravely concerned about the escalation of the present crisis which now poses a serious threat for both Israel and Lebanon and indeed the wider security of the region."

"We urge all parties to do all they can to address this crisis and to prevent the situation from worsening," she said.

In Cairo, Arab League chief Amr Moussa blamed Israel for the deterioration of the regional situation due to its escalated military operations.

Arab foreign ministers also agreed to hold an emergency meeting in Cairo on Saturday to discuss the Israeli attacks on Lebanon and the Palestinian territories.