Mortar fire landed in an open area in Eshkol Regional Council after rocket sirens blared near the Gaza Strip border, IDF Spokesperson's Unit said on Wednesday.
There were no reports of casualties or damage to property in the incident.
The IDF also reported it had detected two more rocket launches from the Palestinian-ruled enclave that haven't crossed the border and landed within the Gaza Strip.
In response, the IDF attacked Hamas targets in the Gaza Strip.
The military announced just shortly before the rocket fire that it was bolstering security presence in the West Bank and on the Gaza border.
"Following situation assessments, it has been decided to reinforce divisions stationed in the West Bank and the Gaza Strip with additional combat troops," a military official said.
Earlier Wednesday, an object wrapped in gift wrap tied to several balloons, suspected to be an explosive device, landed in Sdot HaNegev Regional Council near the Gaza Strip.
Military bomb disposal units and police forces arrived at the scene.
There were no reports of casualties or damage to property in the incident.
The two events came just a day after U.S. President Donald Trump unveiled a long-awaited peace plan for the Middle East on Tuesday, dubbed "Deal of the Century," prompting angry reactions and rejections from the Palestinian leadership.
In reaction to the American peace proposal, thousands of Palestinians rallied in the Gaza Strip Tuesday night, burning photos of Trump and Prime Minister Benjamin Netanyahu.
Palestinian factions also vowed to reignite popular protests throughout the West Bank and Gaza on Friday, dubbed "Day of Rage."
Also on Tuesday, Defense Minister Naftali Bennett and IDF Chief of Staff Aviv Kochavi toured the West Bank to asses security developments within the disputed territory.
At the end of the tour, Bennett said the IDF is prepared in case of instigators on the Palestinian side following through on their threats.
"The IDF and the troops are prepared for any possible scenario," said the defense minister. "We are facing a crucial time which will determine the borders of Israel and its sovereignty. Threats on the Palestinian side will not deter us."
Bennett instructed the troops to prepare for an immediate escalation following the presentation of the peace plan as well as a spike in violence throughout the area in the absence of cooperation from the Palestinian Authority.