Buses carrying Israeli forces could be seen heading to the Gaza border area, where soldiers milled about organizing their equipment. The troop movement was "defensive" but Israel remained prepared for any additional violence from the Palestinian territory, military spokesman Lt. Col. Peter Lerner said.
"Everything we are doing is to de-escalate the situation but on the other hand be prepared for actions that can develop if they do not de-escalate on their behalf," Lerner said.
Israeli defense officials, speaking on condition of anonymity under military guidelines, said the deployment included tanks, artillery and ground forces. Israel's last major operation in Gaza, a territory controlled by the Hamas militant group, took place in late 2012.
Police in east Jerusalem, meanwhile, continued to investigate the disappearance of Mohammed Abu Khdeir. Family members say the 16-year-old was abducted Wednesday shortly before a charred body was found in a Jerusalem forest.
The family has blamed extremist Jews for killing him in revenge for the deaths of the three Israeli teens whose bodies were found in a field in the West Bank on Monday after a more than two-week search.
Israel has accused Hamas of being behind those deaths, and arrested hundreds of Hamas operatives in the West Bank as part of a broad manhunt in the largest ground operation in the West Bank in nearly a decade.
The suspected killing ignited clashes in east Jerusalem between rock-throwing Palestinians and Israeli forces, who responded with stun grenades and rubber-coated bullets on Tuesday. The rioters set tires ablaze and torched three light-rail train shelters, leaving city streets covered in stones and debris.
The situation in east Jerusalem, home to most of the city's Palestinian population, remained tense, though there were no reports of violence Thursday.
Although police were still trying to identify the body at a forensics lab, Abu Khdeir's family set up a mourning tent near a mosque in east Jerusalem. Some 100 people crowded into the tent, including the grand mufti of Jerusalem, the area's top Muslim cleric, to pay their condolences.
The Israeli troop mobilization came as near-daily rocket fire from the Gaza Strip has intensified in the weeks since the Israeli teens disappeared on June 12. Israel has responded with airstrikes.
Two Palestinian militants died in an airstrike last week, and a young Palestinian girl was killed by an errant rocket attack. The Israelis have not suffered any serious casualties.
More than a dozen barrages late Wednesday struck two homes and knocked out electricity in the southern border town of Sderot but caused no injuries. Israel said it responded with overnight airstrikes on 15 Hamas targets. Ashraf al-Kidra, a Palestinian medical official, said 10 civilians were wounded.
Two more rockets fell Thursday, one of them striking an industrial area in southern Israel.
The Israeli military spokesman said security coordination between Israel and Palestinian President Mahmoud Abbas' forces in the West Bank was continuing in order to "limit points of friction" ahead of the first Friday of the Muslim holy month of Ramadan, which is expected to be tense because of the developments. Thousands of Palestinians normally enter Jerusalem to pray at the Al Aqsa Mosque.
Hamas seized Gaza in 2007 from forces loyal to the Western-backed Palestinian President Mahmoud Abbas. Abbas recently formed a unity government backed by Hamas meant to end the seven-year rift, but Hamas, which possesses thousands of rockets, remains in firm control of the coastal strip.
Israel threatened tough action against Hamas in response to the killing of the three teens. Hamas praised their suspected abduction but denied responsibility.
East Jerusalem was quiet Thursday morning but police said units were still patrolling the area. An Associated Press cameraman filmed Hebrew graffiti reading "death to Israel" and "death to Jews."
Police said they were trying to pinpoint the motive behind the killing.
"The investigation is continuing in order to determine whether this was criminal or nationalistic," police spokesman Micky Rosenfeld said.
The incident elicited international condemnation and prompted calls for calm from Israeli leaders.
Prime Minister Benjamin Netanyahu demanded a swift probe of the "reprehensible murder." Abbas said it was clear extremist Jewish settlers were responsible for the death and called on Israel to bring the killers to justice.
Associated Press journalists Yaniv Zohar on the Israeli border with Gaza and Yousur Alhlou in Jerusalem contributed to this report.