Local officials say the toll is expected to rise further, as numerous wounded are in critical condition, and have little to no access to medical care in this remote, war-torn part of Syria.
Around 300 civilians who fled on Tuesday were transferred in trucks to a camp in the northeast.
The SDF believes 400 to 600 militants remain holed up in the enclave, including many hardened foreigners and some emirs.
Over 20,000 civilians have fled in the past 10 days, but the Syrian Democratic Forces said more could still be trapped. Other European countries have remained largely silent about the fate of men and women whom many see as a security threat. There are a lot of Turks. He said the jihadists now held only one square km (0.4 square miles) of the village.
US President Donald Trump said on Monday that the coalition may declare victory over IS in the region in the coming days. "There was no food".
"Most of those who got out are foreigners", Observatory chief Rami Abdel Rahman said.
She said her husband had moved the family across the border into Syria almost three years ago and she did not leave the enclave earlier because of the shelling.
Coalition spokesman Sean Ryan said US-backed forces were facing a fierce fightback.
"The progress is slow and methodical as the enemy is fully entrenched and IS fighters continue to conduct counter attacks", he said.
Air strikes, crucial to SDF gains, have levelled entire districts in the battle against Islamic State, though the coalition says it takes care to avoid hitting civilians.
At least 70 civilians were killed or wounded as a result of air strikes launched by a US-led worldwide coalition on the Syrian village of Baghuz in the south-east of the country, Syria state television reported, citing local sources.
He said the extremist group's "center of gravity" remains in Iraq and Syria, where it reportedly controls between 14,000 and 18,000 militants, and its central leadership maintains "an intent to generate internationally directed attacks".
USA deputy ambassador Jonathan Cohen said the significant military setbacks the IS group has suffered, notably in Iraq, Syria and the southern Philippines, are "a testament" to the work of a global coalition to defeat the extremist group.
But various offensives, including by the SDF and Russia-backed regime forces, have taken back all but a speck of that territory near the village of Baghouz.
To the west of the river, in territory otherwise under the control of the Syrian army and its allies, Islamic State retains a foothold.
His briefing on the latest United Nations report on extremist threats from the IS group and al-Qaida comes as US President Donald Trump has ordered a US troop withdrawal in Syria, saying the IS group has been defeated, and a potential troop pullout in Afghanistan. However, the official said this is making the fighting more hard as the terrorists are working to hold onto their last stronghold.