BEIRUT  - Fierce fighting erupted in northern Lebanon on Monday, further exacerbating tensions after days of deadly sectarian battles that have driven the nation to the brink of full-blown civil war. At least one man was killed in clashes between supporters of the Western-backed government and militants loyal to the Shia Hezbollah-led opposition in the port city of Tripoli, a security official told AFP. Lebanon's ruling Sunni-led majority vowed it would not negotiate with Hezbollah under the gun. The showdown saw Hezbollah gunmen seize large swathes of Muslim west Beirut last week, plunging the already fragile nation into fear and uncertainty. The international community has reacted with alarm to the fighting, which the United States blames on the powerful Shia Muslim group Hezbollah and its Syrian and Iranian patrons. On Monday, Lebanese troops also moved into the Druze mountains southeast of the capital after firefights between rival factions on Sunday left at least 13 people dead, a security official said. Many people have fled the region, where homes were hit by rockets, shop windows broken and cars set ablaze. "Even the Israelis didn't do this to us," said one elderly Druze woman in the town of Shwayfat. "They (Hezbollah) came into our homes, terrified our children and broke everything." Britain condemned the "external interference" in Lebanese affairs. Arab foreign ministers said after crisis talks in Cairo they will send a high-level delegation to Beirut to try to broker talks between the rival factions, but no date has been set. In Beirut, there was an uneasy calm although schools and some businesses remained shut following five days of unrest that has left 47 people dead and scores wounded in the worst sectarian violence since the 1975-1990 civil war. The Masnaa border crossing with Syria was also blocked. In the northern port city of Tripoli, which has also been rocked by sectarian clashes, a security official said three cars with Syrian licence plates came under fire on Monday, leaving three people wounded. Prime Minister Fuad Siniora accused his opposition rivals of staging a "coup" in the multi-confessional nation, which has been without a president for six months because of the political standoff. The crisis is widely seen as an extension of the regional confrontation pitting the United States and its Arab allies against Syria and Iran. Meanwhile a US warship, which was deployed off Lebanon in February amid concern over Lebanon's political crisis, crossed Egypt's Suez Canal on Sunday on its way to the Mediterranean, an official with the canal authority told AFP. The Lebanese daily As-Safir, which is close to the opposition, questioned whether the return of the warship would not encourage the government in its showdown with Hezbollah.