KFAR GILADI, Israel (BBC) - At least 10 people have been killed in a barrage of Hezbollah rocket strikes on northern Israel.

A spokesman for the Israeli ambulance service said Sunday's rocket attacks on northern Israel were the heaviest so far during the conflict.

At least 15 people were injured in the attacks, some of them seriously.

Eyewitnesses said the barrage had lasted more than 15 minutes.

Many of the casualties came in a single attack on the town of Kfar Giladi.

The Arabic news channel Al-Jazeera said those killed were reserve soldiers stationed in the area, but the Israeli army did not confirm this.

Hezbollah guerrillas have fired more than 2,700 missiles at northern Israel since the start of the conflict, causing about a quarter of a million people to flee south out of rocket range. "The scene is very difficult, it can be described as a battlefield," Shimon Abutbul, a rescue worker at the scene, told the Associated Press news agency.

"There was a lot of blood."

He added that this was the worst carnage he had seen in the conflict so far.

Hezbollah has fired more than 3,000 rockets into northern Israel since the conflict began.

Israeli artillery responded with heavy fire across the border into southern Lebanon.

Five Lebanese civilians died early on Sunday in an Israeli air raid on the village of Ansar, according to Lebanese sources.

Reports say three others were killed in an attack on the coastal town of Naquora.

Israeli jets also carried out fresh bombing raids on Beirut's southern suburbs, reportedly striking two districts in the Hezbollah stronghold area. The Israeli military said two reservists had been killed in separate clashes with Hezbollah fighters in southern Lebanon. They were the first reservists to die in the offensive Israeli air strikes targeted roads in Lebanon's eastern Bekaa Valley, virtually cutting it off from the outside world

Positions in the region held by the Popular Front for the Liberation of Palestine were also attacked. The group said one person had been killed. Three Chinese UN peacekeepers are injured in crossfire between Israeli troops and Hezbollah fighters