AMMAN, Jordan (AP) -- Sunni extremists blew up a Shiite mosque in a village in eastern Syria stormed by rebels earlier this week, another sign of the growing sectarian hatred in the country's civil war, activists said Sunday.
They said al-Qaida's affiliate in Syria carried out the destruction. It showed the determination of extremists to drive Shiites out of the village of Hatla in the Deir el-Zour region near Iraq. Last week rebels battled pro-regime militiamen there, killing more than 60 Shiite fighters and civilians, according to activists.
In Lebanon, gunmen deployed in the streets of the northeast and set up roadblocks in protest following the killing of four Lebanese Shiite men in an ambush, security officials said Sunday.
The security officials, speaking on condition of anonymity in line with regulations, said the four were found dead in the Wadi Rafeq area between Ras Baalbek and al-Qaa near the border with Syria.
They said the men were from the powerful Jaafar and Amhaz clans, triggering fears of retaliation.
It was not immediately clear how they were killed or what the motive was, but Sunday's ambush is believed to be related to sectarian tensions related to the Syrian civil war.
Tensions between Sunnis and Shiites in Lebanon increased after the Shiite Iranian-backed Hezbollah openly joined the fight in Syria on the side of President Bashar Assad.
Most Sunnis in Lebanon support the mostly Sunni rebels fighting to oust Assad.
In amateur videos of the mosque destruction in Syria, fighters walked into the mosque in Hatla and trampled on books, some with covers showing pictures of Shiite clerics. The videos then showed an explosion that brought down the building.
Sunday's video posted on the Internet appeared genuine and corresponded with other Associated Press reporting from the area.
Rami Abdul-Rahman, director of the Britain-based Syrian Observatory for Human Rights, said that the mosque was demolished Friday, three days after the battle. Other videos that emerged earlier have showed rebels cursing Shiites and suggested fighters had burned Shiite homes.
"It's clear that they want to root out Hatla's Shiite inhabitants," he told The Associated Press.
The town is home to several thousand people, about 30 percent of them Shiites. It was considered a pro-regime community in the Euphrates River valley, where rebels - including the al-Qaida-linked group Jabhat el-Nusra - have taken over much of the surrounding territory.
The Syrian uprising began more than two years ago with peaceful protests against President Bashar Assad, but later grew into a civil war that has killed 93,000 people and probably many more, according to the U.N.
Most of the armed rebels in Syria are from the country's Sunni majority, while Assad has retained core support among the minorities, including his own Alawite sect, an offshoot of Shiite Islam, along with Christians and Shiites.
In the past year, sectarian bitterness has grown in the conflict. Each sect has been accused of massacres against the other, and Sunni and Shiite fighters from other countries have increasingly joined the battle.
The prolonged civil war has frayed Syria's traditional relations with Jordan and Egypt.
Jordan's King Abdullah II told graduating military cadets Sunday that his forces were ready to fend off any Syrian threats.
Abdullah said Jordan "will emerge victorious in the face of all challenges, the way we always have in the past." His country hosts more than 500,000 Syrian refugees.
Jordan, which backs the rebels against Assad's rule, is concerned that the Syrian president may ultimately attack his neighbors with chemical weapons or that the weapons might fall into the hands of militants if the regime collapses.
Jordan is hosting multinational military exercises involving thousands of U.S. troops. The U.S. has also agreed to install Patriot missiles along Jordan's 375-kilometer (235-mile) border with Syria and is allowing a squadron of 12 to 24 F-16 fighter jets to remain after the exercises.
Also Sunday, a Syrian official said Egypt's decision to cut off diplomatic ties with his country is "irresponsible."
His statement, broadcast on Syria's state TV, came a day after Morsi told supporters in Cairo that his country is severing ties with Damascus and closing its embassy there. Morsi's decision followed calls from hard-line Sunni clerics in Egypt and elsewhere in the region to launch a holy war against Assad's regime.
Morsi also called for a no-fly zone over Syria.
The unnamed Syrian official charged that Morsi's call was a violation of Syria's sovereignty "and serves the goals of Israel and the United States."
Associated Press writers Sarah El Deeb and Zeina Karam in Beirut contributed to this report.