UPDATE: 8:22 a.m. ET: The IDF has released the name of the suspected victim and also said that two other soldiers were killed in the process:

UPDATE: 7:00 a.m. ET: The Israeli military expressed concern that an IDF soldier may have been captured by Hamas as violence erupted early Friday morning in Gaza:

UPDATE: 6:35 a.m. ET: An Israeli spokesperson reportedly said on CNN that Israel did not violate the cease-fire, but acted in self-defense after a deadly assault took place on their forces:

UPDATE: 5:17 a.m. ET: Israel has informed the U.N. that the cease-fire is over, according to at least two reports:

UPDATE — 4:55 a.m. ET: Fighting erupted in south Gaza Friday morning despite a truce that went into effect at 8 a.m. local time.

According to Israeli news website Haaretz, two mortar shells were fired from within the Gaza Stip just two hours after the cease-fire went into effect. They landed in a border town, the outlet reported.

Shortly after, Gaza officials said Israeli tank fire killed four Palestinians.

According to an Israeli government spokesperson, an incident on the border resulted in Israeli casualties and the IDF returned fire in response.

Israel’s South Africa embassy further said on Twitter that “Hamas have now flagrantly violated ceasefire initiated by UN & US.”

GAZA CITY, Gaza Strip (AP) — A three-day cease-fire in the Gaza Strip has gone into effect following heavy Israel-Hamas fighting.

Gaza Cease Fire Crumbles Just Hours After Going Into Effect (UPDATE: IDF Expresses Concern Soldier May Have Been Captured)

Smoke rises after an Israeli strike hit Gaza City, northern Gaza Strip, Thursday, July 31, 2014. (AP Photo/Lefteris Pitarakis)

The cease-fire, announced hours earlier by the U.S. and the U.N., took effect at 8:00 a.m. (0500 GMT) Friday. Secretary of State John Kerry cautioned there were “no guarantees” that the lull would bring an end to the Gaza war, now in its fourth week.

Israel and Hamas both said they would respect the cease-fire but would respond to attacks.

At least four short humanitarian cease-fires have been announced since the conflict began, but each has been broken within a few hours by renewed fighting.

Hours before the cease-fire was to take effect, 17 Palestinians were killed in Israeli strikes. Israel’s military said five soldiers were killed along the Gaza border the previous evening.