What's a howitzer and how are they being used in Ukraine?

The US has helped equip Ukrainian forces with artillery, supplying 90 howitzers – enough to equip five battalions.

The M-777 howitzer is a 155mm piece of artillery known for its accuracy and long-range fire.

Russia also has howitzers, the Msta-B howitzer has a maximum range of 18 miles, making them vulnerable to counter bombardment.

• Video: British Brimstone missiles appear to destroy Russian tanks in Ukraine
• In pictures: Up close with weapons being used on Ukraine frontline
• Russian losses explained: Retired general says one-third of ground forces reduced

Cover image: Army Inform.