BEIRUT -- The Syrian opposition called on Hezbollah to withdraw its fighters from the country immediately, as activists said regime troops supported by pro-government gunmen linked to the Lebanese Shiite militant group battled rebels Sunday for control of a string of villages near the Lebanon-Syria border.
The Syrian National Coalition -- the main Western-backed opposition group -- warned that Hezbollah involvement in Syria's civil war could lead to greater risks in the area, and urged the Lebanese government to "adopt the necessary measures to stop the aggression of Hezbollah" and to control the border to "prevent further risks and to protect civilians in the area."
The statement, posted on the Coalition's Facebook page, coincides with a surge in fighting around the contested town of Qusair in Syria's Homs province near the frontier with Lebanon. Over the past two weeks, the Syrian military, supported by pro-regime militia backed by Hezbollah, has pushed to regain control of the border area -- a strategic region because it links Damascus with the Mediterranean coastal enclave that is the heartland of President Bashar Assad's Alawite sect, an offshoot of Shiite Islam.
It also points to the sectarian nature of the Syrian conflict, which pits a government dominated by the president's Alawite minority against a primarily Sunni Muslim rebellion, as well as fears that the civil war could drag in neighboring states.
The pro-regime gunmen are members of the Popular Committees, which were set up last year in Syria with Hezbollah's backing to protect Syrian villages inhabited by Lebanese Shiites, although rebels accuse the fighters of attacking opposition villages in the area and fighting alongside government forces.
While Hezbollah confirms backing the Popular Committees, it denies taking part in Syria's civil war.
The fighting along the border region has flared in recent weeks, and on Saturday government forces captured the villages of Radwaniyeh and Tel al-Nabi Mando. On Sunday, regime forces shelled the villages of Abu Houri, Saqarigh, Nahriyeh and Ein al-Tanour in the Qusair region, according to the Britain-based Syrian Observatory for Human Rights activist group. It said at least four rebels were killed in the fighting.
Syrian state television said the army was trying to "uproot all the terrorists from the area." The government, which denies it is facing a popular uprising, describes the revolt as a foreign-backed plot and calls those trying to topple it "terrorists."
Lebanon's state-run news agency reported two shells fired from Syria landed Sunday in the town of Hermel near the frontier with Syria, causing material damage but no casualties. A day earlier, two mortar rounds landed in the town for the first time, marking an escalation in violence along the already tense border.
Syria's 2-year-old conflict has repeatedly spilled over into neighboring states, while the violence at home has forced more than 1 million Syrians to escape their homeland to seek safety abroad. Most of the refugees have fled to Lebanon, Jordan, Iraq and Turkey, where they have put an immense burden on already cash-strapped governments to cope with huge influx.
In Jordan, police arrested eight Syrians on suspicion of inciting riots at the sprawling Zaatari refugee camp, according to a Jordanian security official who requested anonymity in line with regulations.
About 100 Syrian refugees threw stones at Jordanian police on Friday for preventing some of them from sneaking out of their desert camp. Ten police officers were injured, including two who remain in critical condition.
The security official said a military prosecutor was set to question the eight suspects later Sunday. If convicted, they face up to three years in jail.
The Zaatari camp houses 150,000 Syrian refugees, while another 350,000 Syrians have found shelter in Jordanian communities. Conditions in the overcrowded camp have worsened since it opened last July, and there have been several riots.
In Damascus, a senior Iranian lawmaker on Sunday expressed support for Assad, and said that what he called the U.S.-led battle to oust the Syrian leader had failed.
Alaeddin Boroujerdi, the head of Iran's parliamentary committee on national interest and foreign policy, said Tehran is "happy that the U.S., with its abilities and regional allies, has failed despite its efforts" to topple Assad.
"Today, they are the losers in the game, no doubt," Boroujerdi told Iranian state TV ahead of talks with Syrian Foreign Minister Walid al-Moallem.
Iran is Syria's chief regional ally.
Al-Moallem repeated the government line that Syria is the victim of a foreign conspiracy hatched by the United States in cooperation with Syria's neighbors. Damascus has previously rebuked Saudi Arabia and Qatar for financing arms purchases to the rebels, and Turkey and Jordan for allowing arms shipments.
The U.S. has long called for Assad to leave power, but for months did not play an active role in backing the rebellion. Recently, however, Washington has grown more assertive, helping cobble together the Syrian National Coalition late last year in the hopes that it could unite the deeply divided opposition and provide a conduit for aid to the rebels.
At an international conference on Saturday in Istanbul that brought together the opposition leadership and its chief international supporters, U.S. Secretary of State John Kerry announced that the Obama administration would double its nonlethal assistance to the Syrian opposition with an additional $123 million in supplies. That could include for the first time armored vehicles, body armor, night vision goggles and other defensive military supplies, officials said.
The additional aid brings total nonlethal U.S. assistance to the opposition to $250 million since the fighting began more than two years ago. Washington has refused so far to provide weapons to Syria's rebels out of fears they could fall in the hands of extremists.
The U.S. pledge was the only tangible, public offer of new international support at the meeting of the foreign ministers of the 11 main countries supporting the opposition and fell well short of what the opposition has been appealing for: weapons and direct military intervention to stop the violence that has killed more than 70,000 people.
The Syrian National Coalition is seeking drone strikes on sites from which the regime has fired missiles, the imposition of no-fly zones and protected humanitarian corridors to ensure the safety of civilians.
Associated Press writers Jamal Halaby in Amman, Jordan, and Maamoun Youssef in Cairo contributed to this report.