Hamas forces have killed an Islamic State group supporter, the first fatality since Gaza's Islamic rulers launched a crackdown on the more-radical group months ago.

Hamas spokesman Eyad Al-Bozum says Tuesday that a 27-year-old man died "during an attempt to arrest him."

He says after the man refused to surrender, Hamas forces opened fire and planted explosives in the house where he was holed up.

The killing comes hours after Islamic State supporters gave Hamas a 48-hour ultimatum to end the crackdown and release dozens of suspected IS loyalists rounded up in recent months.

Hamas blames local Islamic State loyalists for a recent string of small explosions that have targeted Hamas security posts, but often cause no casualties.