Security on Israeli's northern border with Lebanon is being tightened up. This follows a series of Arab guerrilla raids since mid-April in which 51 Israelis -- mainly women and children -- and 17 guerrillas have been killed. Some 80 people have been wounded had at least two guerrillas have been captured.

Several hundred -- exact figures are not known -- Lebanese civilians in southern Lebanon have also been killed by Israeli reprisal attacks following Arab guerrilla activity. The Israeli claim their retaliatory raids were aimed at Palestine guerrilla bases.

The Israelis insist that the Arab raids -- notably on Kiryat Shmoneh, Mealot and Shamir -- were launched from Lebanese territory. Lebanese authorities deny this.

In an attempt to hamper infiltration across the border the Israelis are building a high barbed-wire fence which is heavily patrolled. The success of this scheme may be demonstrated by the last Arab guerrilla raid on Israel's seaside resort of Nahariya, ten miles (15 kilometres) south of the Lebanese border. The guerrillas landed by boat and killed a mother and her tow children and an Israeli soldier on 25 June before being killed themselves.

Having block land-based infiltration, the Israelis are now also heavily patrolling offshore in the border area.

At the end of June Israeli Chief of Staff, General Mordechai Gur, told newsmen that this increasing security survellaince along the border had forced the guerrillas to abandon their positions near the frontier and retreat to the cities and Palestinians refugee camps.

SYNOPSIS: Kiryat Shmoneh, on Israel's northern border with Lebanon.It was here last April that eighteen Israelis were gunned down by Palestinian guerrillas.Eight of them were children and five were women. Since then Israeli authorities have tightened security along the whole length of the troubled frontier.

Since mid-April Arab guerrilla attacks have claimed the lives of fifty-one Israelis on the border -- mainly women and children. Some eighty people have been wounded and seventeen Palestinian guerrillas have been killed.

The Israelis have claimed that all such attacks have been launched from Lebanon. The Lebanese authorities have denied this. But -- in reprisal attacks by Israeli aircraft and artillery - several hundred Lebanese civilians have been killed. The exact numbers are not known. Israeli military spokesmen said these reprisal raids were aimed t guerrilla bases. Now a strongly-patrolled barbed-wire fence is being built along the whole frontier, sealing off further land-based sneak attacks from guerrilla bases just across the frontier.

The last guerrilla raid was launched in late June from the sea. So the Israeli Navy now also keeps a constant watch.