The Israeli military says it is currently conducting extensive strikes in southern Lebanon and the eastern Bekka Valley. 

It comes after Hezbollah fired a ballistic missile that reached the Israeli city of Tel Aviv.

"The IDF is currently conducting extensive strikes in southern Lebanon and the Beqaa area. Details to follow," the military said in a statement.

The Israeli military said it hit more than 280 targets of Hezbollah in Lebanon on Wednesday.

"The strikes destroyed intelligence-gathering tools, command centres and additional infrastructure used by the enemy to build an intelligence situational assessment," the military said in a statement.

Lebanese state media is reporting a strike hit the Shi'ite town of Maaysrah, referring to a place in the mountains of the Christian-majority Keserwan region.

It is the first time the area has been struck in recent hostilities between the Israeli military and Hezbollah.

Lebanon has said at least 51 people were killed and 223 wounded in Israeli strikes across the country.

The health ministry said that an Israeli strike on the village of Joun in the Chouf mountains, south-east of Beirut, killed four people.

It said two other strikes killed three people in the village of Maaysra, north of Beirut, and three in Ain Qana in the south.

Three people have been wounded in a direct hit to home in a northern Israeli Kibbutz during a Hezbollah rocket barrage.

Hezbollah earlier said it had fired a ballistic missile targeting Israeli spy agency Mossad's headquarters near Tel Aviv, saying recent attacks on the militant group had been planned there.

It was the first time a Hezbollah missile has ever reached the Tel Aviv area and it was intercepted by the country's defence system.

There were no reports of damage or casualties and the military said there was no change to civil defence instructions for central Israel.

Norway's security police (PST) have begun a preliminary investigation into reports that a Norwegian-owned company was linked to the sale of pagers to Hezbollah that exploded last week, a police lawyer told Reuters.

Over a two-day period last week, thousands of pagers, as well as walkie-talkies used by Hezbollah operatives, blew up in Lebanon, killing at least 39 people and wounding thousands.

The attacks were widely believed to have been carried out by Israel, which has neither confirmed nor denied its involvement.

It is not clear how and when the pagers were weaponised so they could be remotely detonated. Taiwan, Hungary and Bulgaria are already investigating possible links in the supply chain.

"PST has initiated a preliminary investigation to determine whether there are reasons for starting a (full) investigation on the basis of allegations in the media that a Norwegian-owned company may have been involved in the dissemination of pagers to Hezbollah," PST lawyer Haris Hrenovica said in a text message to Reuters.

Wires