The explosive-rigged vehicle detonated in Al Qahtaniya, a town in Hasakeh province, says the Syrian Observatory for Human Rights, a Britain-based monitor.
A car bombing claimed by Daesh killed five people, including three children, in a militant-held town in northeast Syria on Wednesday, a war monitor said.
Local sources, speaking to the media said the bomb was detonated remotely in front of the town post office.
A militant was also wounded in the attack, sources said.
Regime news agency SANA also reported the bombing, saying it killed several people, including children.
Daesh claimed the attack on its Telegram channel.
The terror group routinely claims attacks in northeast Syria, despite its territorial defeat earlier this year.
Daesh maintains a presence in the country's vast Badia desert, as well as in areas controlled by the PKK terror group's Syrian wing the YPG in the country's northeast and east.
Regime advances after scrapping northwest Syria truce
Regime loyalists captured a town and a village from militants and allied rebels in northwest Syria on Wednesday, after fierce clashes that killed nearly 30 combatants overnight, a war monitor said.
The town of Al Zakat and the Al Arbaeen village in Hama province came under regime control on Wednesday morning, the Syrian Observatory for Human Rights said.
It said the clashes overnight killed 10 regime loyalists and 18 opposition fighters, including 13 militants.
The push has also seen regime loyalists reach the edges of Kafr Zita and Al Latamneh — respectively, a major town and a village — held by the opposition in northern Hama, according to the Observatory.
Hayat Tahrir al Sham (HTS), a militant group led by Syria's former Al Qaeda affiliate, has since January controlled northern Hama as well as all of Idlib and adjacent parts of Aleppo and Latakia governorates.
A truce that started on Friday was supposed to protect three million people living in the region after three months of deadly bombardment by the regime and its ally Russia.
The country's war has killed more than 370,000 people and displaced millions since it started in 2011 with the brutal repression of anti-regime protests.