Lebanese army soldiers patrol near a church outside which suicide bombers blew themselves up in the Christian village of Qaa, in the Bekaa valley, Lebanon June 28, 2016.

Lebanese troops detained 103 Syrians for illegal entry into the country in a security sweep Tuesday, a day after a series of deadly bombings struck a village near the Syrian border, the military said.

The government warned of a mounting challenge in tiny Lebanon, which abuts the war-torn Syria, underlining the magnitude of Monday’s attack that saw nine bombings, eight of them from suicide attackers, strike in the small Christian village of Qaa, killing five people.

“The attack on the Lebanese national security and the unfamiliar manner in which it was executed usher in a new kind of phase in the state’s confrontation with the dark forces of terrorism,” a Cabinet statement said.

The bombings triggered fear and panic among Qaa’s residents and a deepening sense of foreboding in Lebanon, which has grappled for over five years with spillovers from Syria’s civil war.

Tuesday was declared a national day of mourning and authorities postponed funerals for the five killed in Monday’s bombings, citing security reasons. A major religious event scheduled in the capital, Beirut, by the militant Hezbollah group was also postponed.

Also citing security concerns, the ministry of culture postponed the opening of the Bacchus Temple, part of the famed ruins of Baalbek. A troupe of Syrian actors roaming the Bekaa Valley with a performance about refugee woes postponed its tour. A limited curfew was imposed in Qaa and the surrounding area.

The army said it carried out security raids in six areas in the Baalbek region, which has many informal Syrian refugee settlements. It said nine motorcycles and two vehicles were confiscated and two Lebanese were arrested with illegal weapons.

Monday’s explosions, four in the early morning and five at night, also wounded nearly 30 in Qaa. Later in the day, two bombers blew themselves up outside the village church as people gathered for funerals of those killed earlier Monday.

The army said one of the suicide bombers detonated his explosives as he was chased by troops, while the other blew himself up near a military post when guards fired at him. No one was killed but the two blasts wounded 13 people.

Minister of Interior Nouhad Machnouk said initial investigations indicate most of the bombers were from inside Syria and not refugees. He didn’t elaborate.

Private Lebanese OTV aired what it said was footage from security cameras in Qaa, purporting to show a young man involved in the attack. The footage shows the young man with a backpack heading to a gathering outside the church, apparently to blow himself up.

Qaa and the nearby Ras Baalbek are the only two villages with a Christian majority in the predominantly Shiite Hermel region, where the Shiite Hezbollah group holds sway. The group has sent thousands of its fighters to Syria to bolster President Bashar Assad’s forces against the predominantly Sunni rebels trying to topple him.

Hezbollah’s Al-Manar TV blamed Monday’s attack on the Islamic State group. Al-Mustaqbal daily, which is owned by Hezbollah’s rival group, suggested the army was the target of the attack.

No group has claimed responsibility for the bombings.

Sunni extremists have carried out several attacks in the border area since Syria’s conflict began in March 2011, leading the Christians of Qaa to set up self-defense units for their village.