Syria city of Homs under heavy bombardment BEIRUT - Plumes of black smoke rose over the beleaguered Syrian city of Homs on Monday, as the United Nations expressed alarm about the bombardment there and in other rebel-occupied towns. Facing what appeared to be a deteriorating situation, the U.N. issued an urgent call to both sides in the conflict for the evacuation of civilians believed trapped in Homs and another battleground town, Haffah in coastal Latakia province. The Syrian military, reportedly using helicopter gunships and artillery, was attacking on various fronts in a bid to flush out insurgents, and, while it was unclear which side was prevailing, parts of Syria's third-largest city were rapidly being reduced to rubble. "All of Homs is like Bab Amro," said an opposition activist reached inside Homs, referring to a former rebel-controlled Homs neighborhood pummeled this year by weeks of shelling. Other districts, including parts of the old city, appeared to be the targets this time. A BBC correspondent who reached Homs reported mortar strikes every minute, and said Syrian authorities appeared to be using drone aircraft to direct the shelling. One opposition-allied group, Avaaz, issued an "urgent call" for humanitarian access to Homs, which has been the epicenter of the 15-month revolt against the authoritarian rule of President Bashar Assad. Among those injured, Avaaz reported, was well-known "citizen journalist" Waleed Fares, one of many opposition activists dedicated to uploading videos of the violence onto YouTube and otherwise informing the world about what is happening in Syria. "People are dying all around me," Fares told Avaaz from a field hospital, where he was under treatment for a shrapnel wound to his abdomen, the group reported. There are no real medical personnel here, just medical students. The Local Coordination Committees, an opposition group, reported at least 93 people killed Tuesday across the country. There was no independent confirmation of the casualty count. The U.N. observer mission in Syria said it was "not yet able to confirm accounts of large number[s] of casualties" in Homs. However, U.N. observers have "received reports of a large number of civilians, including women and children, trapped inside the town [Homs] and are trying to mediate their evacuation," the U.N. said in a statement. Clashes were also reported in the northwestern province of Idlib and in the capital, Damascus. The official Syrian news agency reported the deaths of "large numbers" of "terrorists" - as the government refers to armed rebels - in both coastal Latakia and Idlib provinces. U.N. special envoy Kofi Annan, whose peace initiative has failed to stem the violence, said he was "gravely concerned" about the shelling in Homs and Haffah. Government opponents seeking to oust Assad have reported augmented shelling and increased deployment of helicopter gunships against rebel-held towns and neighborhoods. The attacks appear to reflect a government effort to reverse rebel territorial gains, while military defections continue. In Washington, State Department spokeswoman Victoria Nuland on Monday called the Syrian government's use of helicopter gunships and irregular militiamen "a very serious escalation" and warned of a "potential massacre" by security forces in Haffah. On Sunday, the opposition reported that an entire military air defense base in Rastan, north of Homs, had defected, and the men had taken their weapons with them. The development raised new concerns about deadly arms falling into the hands of militiamen and possibly ending up on the global weapons market. "Certainly the Syrian arsenal is vast and includes sophisticated surface-to-air missiles as well as chemical and biological weapons," Peter Bouckaert, emergencies director for Human Rights Watch, said from Geneva. The security of these weapons should be a concern for the international community. On Monday,Israel'sdeputy military chief, Maj. Gen. Yair Naveh, warned that Syria's weaponry could someday be used against Israel. "What the Syrians are doing to their own people they will do to us if they have an opportunity," Naveh said, according to the Israel Hayom newspaper. Homs and nearby towns such as Rastan have long been tinderboxes, but the clashes in Latakia highlight how the fighting is spreading. Fierce battles have been reported in recent days in Haffah, a mountain township inland from the port city of Latakia. Claims by both sides in the conflict are difficult to confirm because the government strictly limits the access of outside media. Meanwhile, officials announced that Russian Foreign Minister Sergei Lavrov was scheduled to visit Iran on Wednesday to discuss Syria, among other issues. Russia has proposed an international conference to include many nations. Washington has balked atMoscow's proposed inclusion of Tehran. Special correspondent Rima Marrouch in Beirut and Jerusalem bureau assistant Batsheva Sobelman contributed to this report.