Hamas killed 18 people it said were suspected of being informants for Israel in Gaza. The 18 had been suspected of providing the Israeli military with information as the fighting between the two flared again following the breakdown of ceasefire talks brokered by Egypt.
Gunmen wearing masks killed 7 of the suspected informants near a mosque in Gaza City as worshippers ended their daily midday prayers Friday, according to Hamas and one eyewitness.
Earlier on Friday, 11 men were killed by a firing squad at police headquarters in Gaza City, according to the Al Rai Internet site operated by Hamas.
Two of the people killed were women, said the Palestinian Center of Human Rights. The organization called for a halt to what it described as extra judicial executions.
The killings were portrayed by the Hamas media as the start of a crackdown, under the rallying slogan of choking the collaborators necks.
The killings near the al-Omari Mosque in the downtown area of Gaza took place a day after three top military commanders of Hamas were killed by Israel in a southern Gaza airstrike of a house.
A witness described masked gunmen lining up seven men along a side street and then opening fire. He would only spoke if his identity was not used, fearing for its safety.
These deaths mark the third occasion since the Gaza war started six weeks ago where Hamas has announced it has killed what it says are collaborators.
On Thursday, officials from Hamas said seven were arrested and three were killed for being suspected of helping Israel.
In being able to pinpoint where three commanders from Hamas were location, Israel likely used some local informers.
Israel has kept a network of many informers despite withdrawing in 2005 from Gaza.
Israel has used blackmail or the enticement of exit permits as a way to win cooperation.
At the same time, the fighting between Hamas and Israel continued for the third day since peace talks collapsed earlier in the week.
The renewed bombings and airstrikes have dashed most hopes for a truce after a war of one month has killed more than 2,000 Palestinians.