Three teenage boys tipped 15 litres of hydrochloric acid over the path in a Jewish cemetery in Brighton yesterday evening (Sunday 22 May).
The boys broke into a storage shed at the cemetery in Meadow View, Bevendean, at about 7pm and took three bottles of cleaning fluids which they emptied outside.
A fire crew from Preston Circus in Brighton had to use 4,000 litres of water to dilute the acid, which corroded a significant area of the path.
A police spokesman said that the boys were thought to be aged about 14 or 15 and had a football with them.
One was said to be short with shoulder-length curly hair and wearing a salmon pink top.
The second boy was described as tall and slim and was wearing a black hood.
The third was said to be wearing blue jeans.
A fire service spokesman said that the boys were lucky not to have injured themselves as hydrochloric acid is potentially deadly.
Anyone with information about the identity of the offenders is asked to call Sussex Police on 0845 6070999.