The Russian military has said US-backed rebels have repeatedly violated a ceasefire in Syria, but that the nearly day-old truce has largely held.
Col Sergei Kopytsyn said in a video call from an area near Aleppo that six people have been killed and another 10 have been wounded in the northern city since the truce went into force at sunset on Monday.
Separately, he said two Syrian government troops were killed and another soldier was wounded by opposition shelling of the Castello road, a key route leading to rebel-held parts of Aleppo, on Monday night.
Lt Gen Viktor Poznikhir, of the Russian military's General Staff, said there have been 23 ceasefire violations by US-backed opposition units since the start of the truce.
Meanwhile, the UN envoy for Syria hailed a "significant drop in violence" over the first 24 hours of the new ceasefire.
Staffan de Mistura said no UN humanitarian aid trucks have yet moved across the Turkish border into Syria.
He said UN officials are awaiting assurances that drivers of aid trucks will be "unhindered and untouched".
Mr de Mistura said no letters of authorisation from Syria's government are needed under the US and Russian arrangement, only a simple "notification" to Damascus about the contents of the trucks that "have not yet moved".
He said aid for rebel-held eastern Aleppo is a top priority. He added that a key concern about the overall ceasefire is whether sporadic "incidents" snowball to threaten the deal.