Activists: Deadly air strike at Syrian gas station Updated at 1:11 p.m. (AP) BEIRUT - Regime airstrikes hit a gas station in northern Syria Thursday, setting off a fiery explosion that killed at least 30 people and wounded dozens, opposition activists said. Amateur video showed thick black smoke engulfing the scene. Earlier Thursday, a Syrian military helicopter crashed near the capital of Damascus, and Syria's Information Ministry said the helicopter went down after accidentally clipping the tail of a Syrian passenger plane with 200 people on board. The larger aircraft landed safely at Damascus International Airport and no one was hurt, the Information Ministry said. The airstrikes and the close call in the sky underscored the growing turmoil and violence in Syria. The country is embroiled in a civil war between forces fighting for President Bashar Assad and those trying to topple him. More than 23,000 people have been killed in the conflict, according to activists. In recent weeks, Assad's regime has stepped up airstrikes in northern Syria in an attempt to dislodge rebels from areas they control there. Activists said Thursday's airstrike hit near the town of Ain Issa, about 25 miles from the Turkish border. A day earlier, rebel fighters had seized control of a border crossing north of the town. Rami Abdul-Rahman of the Britain-based Syrian Observatory for Human Rights, said witnesses counted at least 30 bodies and said dozens of people were wounded. Amateur video showed thick black smoke rising near the gas station, which was partially intact. Several vehicles, including a bulldozer and pickup trucks, were on fire. The video, whose authenticity could not be confirmed independently, also showed several damaged cars. A man could be heard shouting "your son is dead." Another group of anti-regime activists, the Local Coordination Committees, reported intense attacks by warplanes on the gas station. The group did not give a death toll, saying only that many people were killed and more than 70 wounded people were taken to a hospital in the provincial capital of Raqqa. Abdul-Rahman quoted one witness as saying the blast was caused by an airstrike but said the Observatory could not independently confirm that. The helicopter crash near Damascus came after the aircraft clipped a Syrian Arab Airlines jet, the state-run news agency SANA quoted Syria's Information Ministry as saying. This seemed to quell speculation that anti-regime fighters might have downed the helicopter. Rebels in Syria are fighting mostly with light weapons. Opposition fighters have claimed to have shot down helicopters and warplanes in the past, although the regime blamed most of the problems on mechanical difficulties. Syrian officials did not report any casualties in the helicopter crash, saying only that it went down in Adra, a Damascus suburb. Adra is near the Douma district, which has witnessed repeated military crackdowns to purge the rebels. "We heard the sound of several explosions and some gunfire, and a few minutes later, we were told that a helicopter had crashed," Mohammad Saeed, an activist in Douma, said via Skype. The helicopter went down in a district known as Tal Kurdi, near a factory for household items, he said, adding that Syrian MiG warplanes and helicopter gunships had been flying low over the area before the crash. After 18 months, the Syrian conflict appears to have reached a stalemate. The rebels are holding some territory despite the government's military superiority but have been unable to score decisive victories. At the same time, the international community is averse to getting involved militarily and instead hopes economic sanctions will squeeze the Assad regime. On Thursday, a coalition including the United States, the European Union and the Arab League met in the Netherlands to search for new ways of isolating the Assad regime. The group called "Friends of the Syrian People" was set up in February after the U.N. Security Council was unable to agree on a resolution condemning Syria's government, due to opposition from Russia and China. Financial experts joined representatives of the group at their meeting in The Hague to help member countries understand how Syria may be using dual-use technologies and front companies to get around the existing sanctions, which include an embargo on oil and arms trade with Syria by participating nations. Dutch Foreign Minister Uri Rosenthal said the sanctions are having an effect, despite non-participation by Russia, China and Iran, citing a sharp fall in Syria's oil exports. Syrian opposition leaders have warned that sanctions alone will not topple Assad. Elsewhere in northern Syria, meanwhile, shelling and gunfire echoed across a border region with Turkey, a day after rebels seized control of the strategic Tel Abyad border crossing there. Tel Abyad is about 25 miles north of where the gas station was struck Thursday. Syria's rebels have captured several other crossings into Turkey and one into Iraq, but Wednesday's seizure of the Tal Abyad post is believed to be the first time they have overrun a frontier post in the northern province of Raqqa.