The Aleppo Media Center and Thiqa News agency, media platforms operated by activists, said the second explosion Friday in Sousian village, about eight kilometers (five miles) north of al-Bab, AP reported.
An earlier explosion in the same village killed at least 60, most of them civilians lining up to return to the town after Daesh retreated.
Al-Bab was captured by the Turkish troops and Syrian fighters backed by Ankara on Thursday, after more than two months of intense fighting.
A Turkish military statement Friday says the Turkish troops and Syrian forces it backs are now in control of all neighborhoods of al-Bab but that efforts to clear it of mines and explosives are continuing. Earlier on Friday, two Turkish soldiers were killed in an explosion near the ISIL-held town of Tadif, south of al-Bab.