Nato's use of graphite bombs to put out of action most of Serbia's electricity supplies is a reminder that the conflict in Yugoslavia is not just being fought with precision-guided weapons.

When graphite bombs detonate, they produce clouds of carbon fibres that cover a substantial area and short-circuit power systems.

Serb technician displays what he says is part of a Nato graphite bomb.

They belong to a class of weapons known as area-impact munitions.

Several other types are already being deployed by Nato forces, and Serbia has similar weapons.

Many of these weapons may leave behind unexploded components that can be as dangerous as anti-personnel land mines.

Cluster bombs

The main area-impact weapon used by the RAF's Harriers is the BL755 cluster bomb produced by Hunting.

• Each bomb contains 147 grenade-sized "bomblets" that disperse over an area the size of a football pitch

• Each bomblet detonates, producing up to 2,000 high-velocity shrapnel fragments

• The effect is similar to a large number of miniature nail bombs exploding simultaneously

• The US Air Force has a similar weapon, the CBU87B, that contains 202 bomblets. More than 10,000 of these were dropped during the 1991 Gulf War

US navy personnel load cluster bombs on to a Harrier jump jet

One problem with these cluster bombs is that many of the bomblets can fail to explode, especially if they hit soft ground.

Many thousands of unexploded bomblets were left behind after the Gulf War in 1991, and there were frequent casualties in Iraq and Kuwait for months afterwards.

Depleted uranium munitions

Nato spokesman Major Dan Baggio: DU munitions contain no more radioactivity than is used in glow-in-the-dark watches

In Kosovo, American A-10 anti-tank aircraft are being widely deployed.

These planes fire another type of weapon - depleted uranium armour-piercing shells.

These are not area-impact weapons as such, but there are reports that the residual matter left behind can cause long-term health problems among people in areas where they have been used.

Multiple-launch rocket system

The Multiple-Launch Rocket System (MLRS) is being deployed in Albania, close to the Kosovo border.

• Each MLRS launcher carries 12 missiles that can be ripple-fired over a range of about 20 miles within a minute

• Each of the missiles is loaded with bomblets, and a single salvo delivers nearly 8,000 sub-munitions over an area of at least 45 acres

• Every bomblet explodes into a hail of anti-personnel shrapnel fragments

Fuel-air bombs

The US air force also has fuel-air explosive bombs that are more devastating than conventional bombs.

• These are the successors to napalm, though typically they cover a wider area and spread out more evenly

• There is also a very powerful "slurry bomb" weighing nearly seven tons and capable of producing blast effects of up to 1,000 psi, not much less than a small tactical nuclear weapon

• So far, neither fuel-air explosives nor slurry bombs have been used in the Kosovo conflict

Serbian arms manufacturers

Area impact munitions are not restricted to Nato, although Serbian forces have not yet used them against Nato targets.

But Serbian arms manufacturers have plenty of experience of producing cluster bombs, and several different types are reported to be deployed.

A young girl wounded in Kosovo during a Nato air raid

They also specialise in very powerful land mines that can be used to destroy armoured formations. One of the most remarkable of these is an array of fuel-air explosive mines.

These are placed in the ground over an area of at least 1,000 square yards. and are designed to detonate together, with each mine ejecting a fuel mixture vertically to form a single aerosol cloud that explodes in a single massive blast.

This weapon was advertised openly in defence magazines in the mid-1990s, with the claim that it produced an effect as damaging as a 1-kiloton nuclear blast.

Risks to civilians

Graphite and cluster bombs have already been used in the Kosovo conflict, and anti-tank planes with DU weapons have been deployed.

If the conflict escalates further - especially if there is a major ground war - then it is well-nigh certain that other area-impact weapons will be used.

They will add greatly to the devastation caused by the war, and increase the risk of further civilian casualties.