Five Palestinian demonstrators were killed Wednesday night by an explosive device during clashes with the Israeli army near the border with Gaza, the Palestinian Authority’s health ministry said, citing AFP.

A crowd of Palestinians, many of them teenagers, had gathered near the border with Israel when violence erupted, according to witnesses and the Israeli military.

A witness told AFP that an explosive device held by a protester exploded.

The health ministry, led by Gaza’s ruling party Hamas, said five Palestinians were killed and 19 wounded in the blast, but gave no further details.

“The device exploded a few meters from the wall (which separates Israel from Gaza),” a source in the Palestinian security services told AFP.

The border demonstration was organized to mark the 18th anniversary of Israel’s withdrawal from the Gaza Strip and the 30th anniversary of the Israeli-Palestinian Oslo Accords on Palestinian autonomy.

The Israeli army said in a statement that “hundreds of people took part in riots near the security fence in the northern Gaza Strip.”

“There was an attempt to throw an explosive device at the soldiers. The device exploded in the Gaza Strip, injuring several protesters,” the army said.