A California student was held on the U.S.-Canada border Monday and accused of plotting to help a terror group and join al-Qaida, as well as talking about attacking Los Angeles, officials said.

Nicholas Teausant, 20, who was allegedly planning to join the Islamic State of Iraq and Syria, was charged with attempting to provide material support to a foreign terrorist organization.

Iran's foreign minister said Monday that Tehran is "ready to help any logical attempts" to end the Syrian conflict, during a visit by U.N.-Arab League envoy to Syria Lakhdar Brahimi.

Brahimi was in Tehran for the second day of talks with Iranian officials about ending the conflict in Syria, a key regional ally of Iran.

Six people were killed and 20 wounded Monday by a car bomb in a Homs district that is home to members of Syrian President Bashar Assad's Alawite sect, a monitoring group said.

"At least six people were killed, including women and children, and 20 others wounded in a car bomb attack on the Zahraa district," said the Syrian Observatory for Human Rights, a Britain-based group with a network of contacts inside Syria.

Syrian regime forces were on Monday readying an assault on the last rebel-held areas in the Qalamoun mountains, strategically located on the Lebanese border, after overrunning key opposition bastion Yabrud.

The capture of Yabrud on Sunday by Syrian troops and Hizbullah fighters came shortly after the conflict entered its fourth year and marked a significant setback for the rebels as it severs their supply lines from across the border.

The Lebanese army announced on Monday that it has arrested a number of Lebanese and Syrians for attempting to illegally enter Lebanon.

It said in a statement that it detained the two Lebanese and 19 Syrians in the Wadi Khaled region near Syria in the North.

Secretary of State John Kerry announced Monday career diplomat Daniel Rubinstein has been named U.S. special envoy for Syria as it enters the fourth year of a devastating civil war.

Rubinstein replaces Robert Ford, the former U.S. ambassador to Syria, who resigned as special envoy last month.

Syrian regime forces were Monday readying an assault on the last rebel-held areas in the Qalamoun mountains, strategically located on the Lebanese border, after overrunning key opposition bastion Yabrud.

The capture on Sunday of Yabrud by Syrian troops and fighters of Lebanon's Hizbullah marked a significant setback for the rebels as it severs their important supply lines from across the Lebanese border.

The Lebanese army blew up on Monday a booby-trapped vehicle found on the Fakha-Ras Baalbek road in eastern Lebanon, after firing an RPG-7 rocket on it, the military and the state-run National News Agency reported.

The army said in a communique that it blew up the car, which contained 170 kilograms of explosives, after the military expert inspected it and found difficulty in defusing it.

The U.N.-Arab League envoy for Syria, Lakhdar Brahimi, arrived in Tehran on Sunday for talks on the Syria crisis with top Iranian officials, media reports said.

The Fars news agency said he would meet President Hassan Rouhani and Foreign Minister Mohammad Javad Zarif and other officials during his three-day visit.

Arsal residents condemned Sunday the firing of rockets from the Eastern Mountain Range, urging the army to deploy in the area, as the only road linking the town to al-Labweh and Lebanese regions was reopened.

“We denounce all kinds of terrorism and the firing of rockets from the eastern mountain range,” a statement issued by the prominent figures of the Bekaa town of Arsal's following a meeting at the municipality of the town.