Syria: Dozens dead in clashes between pro-government and Kurdish-led forces
The SDF said in a statement that it had "driven out the regime gunmen who had infiltrated the Dheiban area" of Deir Ezzor province.
It added that the pro-government forces had crossed the Euphrates "under cover of an indiscriminate bombardment" of its positions.
The SOHR said 21 of those killed were pro-government and three were SDF fighters, while another woman was also killed.
Conflict between the SDF and local Arab groups in Deir Ezzor has become more frequent in recent months.
Earlier this month 10 days of fighting between the SDF and armed Arab tribesmen saw 90 people killed.
Local tribal groups have accused the SDF of autocratic behaviour in the Arab-majority region, while the SDF has accused the Syrian government of stirring up discontent.
One of the main demands of the tribes has been an end to SDF rule and the creation of an independent military council made up of local Arabs that would coordinate security and economic assistance directly with the US.
'Growing Syrian crisis'
Speaking to news outlet Al-Majalla last week, SDF military commander Mazloum Abdi said it was ready to compromise with Damascus in Deir Ezzor but so far the government had shown no willingness to do so.
"We asked the Russians to help reach a political solution that would end the growing Syrian crisis," he said.
"We ask that Damascus accept a realistic political solution... and Damascus still insists on its policy of stubbornness and rejects any realistic proposals that will end the crisis and contribute to peace and stability."
Fighting broke out in the oil-rich province on 27 August, when the SDF detained Ahmad al-Khabil, better known as Abu Khawla, the controversial head of the Deir Ezzor military council, amid suspicion he was conspiring to oust the US-backed force from the region, MEE previously reported.
The SDF has wrested back control of the territory from the rebelling tribes.
The US has warned that fighting between the tribes and SDF distracted from the focus of preventing an Islamic State resurgence.
While some of the Arab tribes work with the SDF and the US, other factions maintain ties to Damascus.