A Syrian rights group says a blast in northeast Syria has killed at least 30 people and wounded dozens of others.

The Britain-based Syrian Observatory for Human Rights quotes witnesses as saying the blast occurred when an air strike hit a fuel station in al-Raqqa province Thursday. The group's director says witnesses told him they saw at least 30 bodies, with the death toll likely to rise.

Earlier reports said at least 50 were killed in the blast.

Meanwhile, Syrian state television says a military helicopter that crashed near Damascus clipped the tail of a Syrian passenger plane in midair. The report said the passenger jet landed safely Thursday at Damascus International Airport with 200 people onboard.

Opposition activists said rebels shot down the helicopter. Fighters opposed to Syrian President Bashar al-Assad have claimed to have downed military helicopters before, including late last month in Damascus.

The Syrian state report did not include eye witnesses to the alleged incident.

VOA correspondent Elizabeth Arrott reported heavy shelling in the capital Thursday. She says classrooms are crowded in the al-Abbassiyin neighborhood not far from the shelling, as parents bring their children from nearby towns where fighting rages.

Meanwhile, U.N. Secretary-General Ban Ki-moon says the government and the opposition in Syria appear determined to resolve the crisis militarily. He told reporters Wednesday that military means will not bring an answer, and the crisis should be resolved through political dialogue.

Mr. Ban said Syria will be a top issue as he meets with world leaders at the U.N. General Assembly, saying they must urgently address the situation.