Six people were wounded, one in serious condition, two in moderate condition and the rest sustained light injuries, localnewspaper The Jerusalem Post reported, citing rescuers.

The number of casualties was expected to rise further as some people were feared to be still buried under the debris. Haifa, the third largest Israeli city and a key commercial center, is about 30 km south of the Lebanese-Israeli border. The city has come under repeated rocket attacks by Hizbollah guerillas in recent days.

On Sunday, eight Israelis were killed and dozens of others wounded in Hizbollah rocket attacks on Haifa.

In response, Israel has stepped up air raids on Lebanese targets and a small group of Israeli ground forces entered southern Lebanon, targeting Hizbollah strongholds in the border area.

Violence between the two sides erupted when Hizbollah guerillas abducted two Israeli soldiers and killed eight during cross-border clashes on July 12.