Syrian President Bashar Assad's forces resumed the firing Scud missiles against rebels in the country, The New York Times, citing US officials reported Thursday.“We’ve been clear that we have seen the regime in Syria use Scud missiles against its own people, and that continues,” the Times quoted a senior State Department official as saying. According to the report, US officials do not believe the missiles were armed with chemical weapons.The Times said that one of the Scud attacks took place on Thursday near Maara, a town north of Aleppo near the Turkish border.The Times also quoted a US Defense Department official as saying that “We know they’ve been firing Scuds and continue to fire them.”On December 12, the Times reported that six Scud missiles had been fired from the Damascus area at Free Syrian Army targets, the first such attack inside the country.In response, a senior US official was quoted by the Times as saying that the Obama administration viewed Assad's use of Scud missiles as a "significant escalation" of the conflict.Syrian foreign minister Walid al-Moallem, however, issued a statement denying that Syria had used Scuds. It called the reports “untrue rumors.”According to the Times, Syria has several types of Scuds, including Scud-B systems that were provided by Russia and Scud-C’s and Scud-D’s that were developed with the assistance of Iran and North Korea.UN investigators warn of sectarian tensionsUnited Nations human rights investigators warned on Thursday that the war in Syria was becoming increasingly divided across sectarian lines, pitting the ruling Alawite community against the majority Sunnis."As battles between government forces and anti-government armed groups approach the end of their second year, the conflict has become overtly sectarian in nature," the independent investigators led by Brazilian expert Paulo Pinheiro said in their latest 10-page report.The conduct of hostilities by both sides is "increasingly in breach of international law," the statement added.The investigators attributed these developments to more civilians seeking to arm themselves and to foreign fighters - mostly Sunnis - flocking into Syria from 29 countries."They come from all over, Europe and America, and especially the neighboring countries," said Karen Abuzayd, one of UN investigators, told a news conference in Brussels.In response, Syrian government forces have increased their use of aerial bombardments, including shelling of hospitals, and evidence suggests that such attacks are "disproportionate," the investigators said.The deepened sectarian divisions may diminish prospects for post-conflict reconciliation even if Assad is ousted, and the influx of foreigners raises the risk of fighting spilling into neighboring countries riven by similar communal fault lines.Rebels fight for strategic town in Hama provinceRebels thrust into a strategic town in Syria's central Hama province on Thursday, activists said, pursuing a string of territorial gains to help cut army supply lines and cement a foothold in the capital Damascus to the south.They have made a series of advances across the country, seizing several military installations and more heavy weaponry, hardening the threat to Assad's power base in Damascus 21 months into an uprising against his rule.Rebels said a day earlier they had captured at least six towns in Hama province. On Thursday heavy fighting erupted in Morek, a town on the highway that runs from Damascus north to Aleppo, Syria's largest city and another battleground.Fighting in Hama could aggravate Syria's sectarian strife as it is home to many rural minority communities of Alawites and Christians. Minorities, and particularly the Alawite sect to which Assad himself belongs, have largely backed the president. Syria's Sunni Muslim majority has been the engine of the revolt.President Vladimir Putin of Russia, Assad's main ally and arms supplier, warned that any solution to the conflict must ensure government and rebel forces do not merely swap roles and fight on forever. It appeared to be his first direct comment on the possibility of a post-Assad Syria.The West and some Arab states accuse Russia of shielding Assad after Moscow blocked three UN Security Council resolutions intended to increase pressure on Damascus to end the violence, which has killed more than 40,000 people.