Gunmen stormed a pro-government television station in Syria Wednesday, slaughtering seven employees, wounding others and taking several people hostage. The attack came a day after President Bashar al-Assad declared Syria to be in “a real state of war.”

Killed in the early morning attack on Ikhbariya TV, located in a southern suburb of Damascus, were three journalists and four security guards. The attackers fired automatic weapons and rocket-propelled grenades at the security guards before ransacking the satellite station’s offices and studios and then setting powerful explosive devices that reduced the buildings to broken and burning rubble.

An outside wall of one of the buildings was splattered with blood, where the station’s employees had been bound, forced to their knees and then executed in cold blood.

The assault on Ikhbariya TV came just one day after the European Union issued new sanctions on sections of Syria’s state-run media, and followed the move earlier this month by the Arab League to force two Pan-Arab satellite companies to black out Syrian channels.

The massacre is part of an escalation of attacks by the so-called Free Syrian Army and other insurgent militias. These groups are backed by the Western powers, which are, together with Turkey and the right-wing monarchical regimes of Saudi Arabia and the Gulf states, providing them with an increasingly sophisticated arsenal as well as “trainers”, “advisors” and foreign fighters from elsewhere in the Middle East.

Wednesday’s assault on the TV station followed reports Tuesday of an attack on a major Republican Guard compound in Damascus as well as ambushes of government troops elsewhere in the country.

The escalating violence inside the country has been joined by stepped-up external threats, particularly from Turkey, which has ratcheted up tensions in response to Syria’s shooting down of one its military jets over Syrian territory late last week. The Turkish press reported Wednesday that Turkey had deployed 15 battle tanks, armored vehicles and artillery to its southern border with Syria. The Turkish government has vowed to treat any Syrian forces approaching the 550-mile long frontier between the two countries as hostile and respond militarily.

Violence inside Syria has “reached or even surpassed” the levels that existed before the April 12 ceasefire agreement brokered by the UN-Arab League envoy Kofi Annan, Jean-Marie Guehenno, the UN’s deputy envoy, told the UN Human Rights Council (UNHRC) Wednesday. He added that the six-point Annan agreement “is clearly not being implemented.”

The UNHRC received an update from an international commission of inquiry into the Syrian events, which warned that the conflict was rapidly developing into a sectarian civil war.

“Where previously victims were targeted on the basis of their being pro- or anti-Government, the CoI [Commission of Inquiry] has recorded a growing number of incidents where victims appear to have been targeted because of their religious affiliation,” the report states.

A large portion of the document is devoted to the massacre in Houla, northwest of the city of Homs, late last month. The killing of some 100 civilians was seized upon by Washington and the other Western powers and the mass media in the West to demand the immediate ouster of the Assad regime, which they held responsible for the killings.

Subsequent reports have appeared, particularly one written for Germany’s leading daily newspaper, Frankfurter Allgemeine Zeitung, that have cited eyewitness testimony, including from opponents of the Assad regime, that the real authors of the killing were members of the Free Syrian Army, and that the victims were members of the Shia religious minority as well as perceived supporters of the government.

The report to the UN acknowledged that the investigation could not say with certainty who had carried out the killings. It presented three possibilities: “First, that the perpetrators were Shabbiha or other local militia from neighbouring villages, possibly operating together with, or with the acquiescence of, the Government security forces; second, that the perpetrators were anti-Government forces seeking to escalate the conflict while punishing those that failed to support—or who actively opposed—the rebellion; or third, foreign groups with unknown affiliation.”

The commission of inquiry, the report said, “could not rule out any of these possibilities,” although UN officials suggested that pro-government militias were the most likely suspects.

The report itself, however, cited evidence to the contrary, including information that the victims included one retired and one active member of the Syrian security forces, and that one of the children killed was wearing a bracelet bearing the Syrian national flag. It also cited testimony that the killers had “shaved heads and long beards”, suggesting the Sunni Islamist forces, including foreign fighters, that have been mobilized against the regime.

Russia, which has opposed until now the US-led demand for regime change in Syria, criticized the UN report for failing to reflect the scale of violence unleashed by the Western-backed “rebels.”

The report “does not reflect the scope of violence committed by militants,” said Vassily Nebenzya, the director of the Russian Foreign Ministry’s department for humanitarian cooperation and human rights. These forces, he said, “kill or take hostage civilians, renowned Syrian political, state, municipal, public and religious activists, pilgrims”.

He added: “State institutions and infrastructure facilities are attacked practically on a daily basis. A mine war is in full swing. Militants commit bloody terrorist acts in Syrian cities.” This violence, Nebenzya said, “is fed with money and weapons from abroad.”