Updated

The Latest on developments related to Gaza protests (all times local):

1:05 p.m.

Israel's defense minister says Gaza's Hamas rulers are the "only culprits" in the death of a Palestinian boy who was killed by Israeli army fire in protests on the Gaza-Israel border.

Avigdor Lieberman alleged on Twitter that Hamas uses women and children as human shields. His comments Saturday came after a top U.N. envoy in the region, Nikolay Mladenov, said it is "outrageous to shoot at children" and demanded an investigation.

The Israeli military has not commented on the killing of Mohammed Ayyoub. Gaza health officials initially gave his age as 15, but a local rights group, citing official documents, said he was 14.

Ayyoub was one of four Palestinians killed Friday by Israeli army fire in the fourth round of weekly border protests led by the Islamic militant Hamas.

___

8:30 a.m.

Health officials say Israeli soldiers firing from across a border fence have killed four Palestinians, including a 15-year-old boy, and wounded more than 150 others as several thousand people in blockaded Gaza staged a fourth round of weekly protests on the border with Israel.

Huge black plumes of smoke from burning tires engulfed the border area on Friday. Some of the activists threw stones toward the fence or flew kites with flaming rags dangling from their tails.

The latest deaths brought to 32 the number of Palestinians killed by Israeli troops in protests since late March. More than 1,600 have been wounded by live rounds in the past three weeks, according to the Gaza Health Ministry.