By turns defiant and threatening, President Bashar Assad is vowing to use an “iron hand” to crush what he called the terrorists and saboteurs behind Syria’s 10-month-old uprising in which thousands of people have been killed.

In his first speech since June, Assad showed a steely confidence in the face of the uprising, one of the bloodiest of the Arab Spring. But opponents called Tuesday’s speech a rambling address by a leader who is dangerously out of touch.

Assad repeated his past claims that a foreign conspiracy and terrorists are driving the revolt, not peaceful protesters seeking to reform the country.

The conflict in Syria is entering a new and heightened phase, with army defectors and some members of the opposition increasingly turning their weapons on government targets. The regime, in turn, has intensified an already deadly military assault, and a UN official said Tuesday that about 400 people have been killed in the last three weeks alone, on top of an earlier UN estimate of more than 5,000 dead since March.

Since 23 December, three mysterious blasts have struck the capital, killing scores of people in the kind of violence more commonly seen in neighbouring Iraq. It’s unclear who is behind the bombings, which the regime said were suicide attacks.

The regime has blamed “terrorists” for the explosions, saying they proved that Syria was fighting armed gangs. But the opposition accuses forces loyal to the regime of carrying out the attacks as a way to tarnish the uprising.

Assad also denounced the Arab League, which sent a team of observers into Syria in late December to assess whether the regime is abiding by an Arab-brokered peace plan that the regime agreed to on 19 December. On Monday, a group of Arab League observers was reportedly attacked in northern Syria, suffering minor injuries.

New deaths were reported Tuesday, with activists saying security forces killed at least 10 people in the eastern city of Deir el-Zour, despite the presence of an Arab observer mission in the area.

Assad, 46, inherited power 11 years ago from his father and has adopted tactics similar to those of other autocratic leaders in the region who scrambled to put down uprisings by unleashing a crackdown on their people.

The formula failed in Tunisia and Egypt, where popular demands increased almost daily — until people accepted nothing less than the ouster of the regime. But Syria’s conflict has gone on far longer, and the death toll is mounting daily.

“We will declare victory soon,” Assad said, insisting that he still has the support of his people. “When I leave this post, it will be also based upon the people’s wishes,” he added.

Regime opponents denounced the speech.

“Bashar is completely removed from reality, as if he is talking about a country other than Syria,” said Abu Hamza, a Syria-based activist who asked to be identified only by his nickname because of fear of reprisals by the regime.

Syria has banned most foreign journalists and prevented independent reporting, making activist accounts and amateur videos posted online key sources of information about the uprising and crackdown.

Assad accused foreign media outlets and websites of working against Syria, even claiming that an interview he gave to ABC’s Barbara Walters last month was altered. He was widely criticised for the interview, in which denied ordering the suppression of the protests.

ABC News spokesman Jeffrey Schneider denied the interview had been altered in any way.