The Palestinian Interior Ministry in Gaza has accused Israel of a cross-border shooting in violation of a truce.
An Israeli military spokeswoman said "we have no knowledge of such an incident".
The Palestinian ministry in the coastal territory dominated by Hamas Islamists said Israeli troops shot at houses east of the town of Khan Younis.
The ceasefire, renewed on Thursday for five days after a previous truce expired, has largely halted more than a month of fighting in which 1,945 Palestinians, many of them civilians, 64 Israeli soldiers and three civilians in Israel were killed.
The truce got off to a rocky start with Israel launching an air raid early on Thursday in response to rocket fire from Gaza in violation of the earlier truce.
There were no reported casualties in any of these incidents.