Ref: http://www.moonofalabama.org/2016/09/us-allies-volunteer-to-share-blame-for-deir-ezzor-attack.html#more

...Early Sunday Australia jumped in claiming its jets had taken part in the attack:

Australian aircraft were involved in a US-led coalition operation which killed dozens of Syrian soldiers stationed near Eastern ISIS stronghold city of Deir Ezzor, the Australia's Defense Department confirmed.
...
"Australian aircraft were among a number of international aircraft taking part in this Coalition operation," the Defense Department said in a statement.

Late Sunday the Danes followed:

"Two Danish F-16 [fighter aircraft] participated in these attacks along with the aircraft of other nations. The strikes had been stopped immediately after the Russian side reported that the positions of the Syrian servicemen had been hit," the military command authority of the Danish Armed Forces said in a statement issued Sunday.

This morning, the BBC defense correspondent says, the UK also claimed guilty:

Jonathan Beale @bealejonathan

BBC understands @RoyalAirForce jets might have been involved in #Syria Airstrikes that killed 60 + Syrian soldiers.

Four planes attacked and four, now five airforces claim to have been part of it? That is neither plausible nor realistic.

Also: http://www.german-foreign-policy.com/en/fulltext/58971

BERLIN/DAMASCUS/WASHINGTON
(Own report) - The German Bundeswehr's concrete role in the widely criticized air attacks carried out by the anti-IS coalition and its members has not become clear, even after the coalition's air strikes on Syrian government forces near Deir al-Zor. The Bundeswehr is supporting air strikes on IS/DAESH not only by furnishing in-flight refueling - already more than 1,100 times - but also by supplying intelligence information. This information is passed on to all coalition members through the "information space" in the anti-IS coalition's Combined Air and Space Operations Center at the Al Udeid Air Base (Qatar), where several Bundeswehr officers are stationed. Observers assume that some of this intelligence, for example, can be used also by Turkey to prepare its operations against Kurdish units in Northern Syria. It is not clear, whether this data has played a role also in preparing attacks, resulting in civilian casualties, such as the anti-IS coalition's air strikes on Manbij in mid-July, wherein more than 100 people were killed. Last June, the Bundeswehr declared that it had already evaluated more than 11,000 reconnaissance photos and passed them on to its allies fighting the war against IS.