The “humanitarian bombing pause” declared by Russia and Syria in the besieged city of Aleppo has gone into effect, but as ABC News delicately puts it, “doubts have already been raised about the credibility of the brief pause.”

“There is no sound of planes, but we can still hear shootings on the ground,” Wissam Zarqa, a teacher in Aleppo’s al-Mashhad neighborhood, told ABC News. “The government is still trying to advance. As long as fighting and clashes are ongoing it is not possible for civilians to leave. Some elderly people who can’t keep living under siege might want to leave but they can’t because it’s not safe.”

Even if he felt it was safe to leave, he would choose to stay, he said.

“We don’t feel like leaving our homes and becoming refugees,” he said. “None of my friends are considering leaving.”

The BBC reports that “rebels have rejected the truce, with reports of continued clashes and few residents heeding calls to leave.” Rebel and government forces blamed each other for exchanges of fire in the supposedly safe “humanitarian corridors.”

Russia appears to have heeded complaints by U.N. officials that a bombing pause of only a few hours was insufficient to evacuate wounded or bring much-needed supplies into Aleppo, as President Vladimir Putin ordered the pause extended for an extra 24 hours until 16:00 local time on Friday.

The European Union was quick to inform Russia that fresh sanctions will be imposed if the bombing of Aleppo resumes.

“We must show that robust and united European stance in the face of Russian aggression,” declared British Prime Minister Theresa May. “It’s vital that we work together to continue to put pressure on Russia to stop its appalling atrocities, its sickening atrocities in Syria.”

“All the options are open as long as the truce is not respected and as long as there is a will to crush a city, Aleppo,” seconded France’s President Francois Hollande.

Some other EU ministers were not as forceful about the possibility of sanctions, however, and the current version of their draft resolution vaguely states that “those responsible for breaches of international humanitarian law and human rights law must be held accountable.”

There are indications Russia plans to resume and intensify its bombing campaign. On Wednesday, a senior NATO diplomat told SwissInfo that “Russian warships off the coast of Norway are carrying fighter bombers that are likely to reinforce a final assault on the besieged Syrian city of Aleppo in two weeks.”

“They are deploying all of the Northern fleet and much of the Baltic fleet in the largest surface deployment since the end of the Cold War,” the NATO source added. “This is not a friendly port call. In two weeks, we will see a crescendo of air attacks on Aleppo as part of Russia’s strategy to declare victory there.”

According to SwissInfo, the Norwegian military concurred that the Russian fleet would “probably play a role in the deciding battle for Aleppo.”