Tensions are running high along the Lebanese-Israeli border. Mohalhel Fakih reports from Beirut Lebanon and Israel have each sought the intervention of the United Nations Security Council after an Israeli civilian was killed in cross-border fire from Hizbullah on Sunday and Beirut residents were rattled early Monday morning by sonic booms from Israeli fighter planes. Hizbullah said it had targeted Israeli jets breaching Lebanese airspace when shrapnel fell on the Israeli border town of Shlomi, killing one person and wounding five others. A few hours later, Israeli warplanes swooped over Beirut. Israel said the attack was deliberate and officials threatened both Syria and Lebanon with severe retaliation if they did not rein in the Muslim Shi'ite group, which controls large swathes of the border region. Israeli warplanes had also struck near the south Lebanon village of Tayr Harfa, causing only material damage. Those incidents came two days after Hizbullah rocketed Israeli positions in the Shebaa Farms, a border area occupied by Israel since 1967. The UN views all attacks on the Shebaa Farms and Israeli air forays into Lebanon as breaches of the May 2000 terms of Israel's pull out from Lebanon. Officials in Beirut had blamed Israel for the assassination of a veteran Hizbullah fighter, Ali Hussein Saleh, in a bomb blast in the capital last week. Beirut had protested to the Security Council, which is currently chaired by non- permanent member Syria, over Israel's "aggression, threats and its continuous and provocative violations of the airspace and sovereignty of Lebanon". Lebanese President Emile Lahoud, who described Israel's assassination last week of veteran Hizbullah fighter Saleh a "terrorist" attack, said Israel should be blamed for shattering calm in the region. "The cause of the latest incidents in the south are daily Israeli violations that the United Nations has condemned following the liberation of the south from Israeli occupation," Lahoud said in a statement. He also condemned as "air terrorism" low swoops over Beirut by Israeli fighter jets. Syria also accused Israel of deliberately escalating tensions. Syrian radio said "Israel wants to appear as a victim although it is the aggressor." "Israel, which stirred up the events in southern Lebanon, wants to increase an already tense situation in the region by playing the tune of threats and warnings," it added. Israel also filed a complaint on Saturday with the Security Council against Syria's backing for Hizbullah, although diplomatic channels are not the only means it is expected to use in response to the death of one of its citizens. "We have chosen to react to Hizbullah's attacks by stressing diplomatic action while still mounting a retaliatory operation on the ground," Deputy Defence Minister Zeev Boim said. Israeli officials have hinted that Syrian targets in Lebanon could be next. "Syria is definitely the umbilical cord from which Hizbullah feeds," Boim said. His comments followed media reports that Israel had sent warnings to Beirut and Damascus through the United States and the UN that Syrian targets in Lebanon would be attacked if Hizbullah struck again. The group said it was ready and fully prepared to face any Israeli operation. Hizbullah's representative in southern Lebanon Sheikh Nabil Qawook vowed to continue to "respond to Israel's violations and provocations". Hizbullah's Deputy Secretary-General Sheikh Naim Qassem followed up with a statement that dashed any US and Israeli hopes that the recent war on Iraq and mounting American pressure on Syria could alter the group's agenda. "The recent operation in Shebaa Farms was part of our defence operations that we are committed to until the area is liberated from occupation. We did not carry out this action in reaction to something else -- it was a defensive action. The timing and circumstances caused us to launch this operation." Sunday's strike will likely increase US ire over the group's military presence along the border. "We have made clear to Lebanon and Syria our serious concern over this calculated and provocative escalation by Hizbullah," US State Department Spokesman Philip Rieker said after Hizbullah's strike on the Shebaa Farms on Friday. The US official urged both Beirut and Damascus to maintain calm along the Israel-Lebanon border, mentioning a UN Security Council statement that had commended both Israel and Lebanon for the stability in the border area. UN Special Envoy for Lebanon Steffan de Mistura reiterated calls for restraint. "We are appealing to all sides... to stop this time of potential escalation. Overflights should not take place over Lebanon." He also denounced anti-aircraft fire, which he said was "most of the time correlated to overflights". The UN envoy's comments contrasted with Secretary-General Kofi Annan's harsh statement, in which he condemned Hizbullah's strike on Sunday and called on "all governments that have influence on Hizbullah to deter it from any further actions which could increase the tension in the area." He urged Israel "to exercise utmost restraint". Annan's statement drew a sharp rebuke from Hizbollah, which slammed the UN Secretary General as a "spokesman" in the name of Israel and the United States, and charged him with "bias" in favour of Israel.