Construction work had to be stopped and the army's bomb disposal team was called in after an old shell was found at the Merebank site in Avonmouth.
Builders, who are currently putting together a recycling plant off Kings Weston Road for SITA UK, found the shell in the ground of what used to be an old mustard gas factory. Other work in the vicinity then had to be stopped as police believed that there might be more shells buried in the earth.
The site was part of the former Britannia zinc smelting works and a section was closed off after the discovery, according to the Bristol Evening Post.
"Construction workers had uncovered a possible incendiary device at the scene on an old mustard gas factory. We called EOD (the army's bomb disposal team) and a cordon was put in place. They attended and two devices were removed but it is believed there are a number of other devices that may be buried.
These will be located and uncovered," said a spokesperson for Avon and Somerset Police.
A representative of SITA told the news source that the Ministry of Defence (MoD) will be asked for advice before further work continues in the area where the shells were discovered.
It is not the first time that problems have affected the site. Earlier this year work was halted after two contractors complained of suffering from nosebleeds. Due to the plot's previous history, where mustard gas was used to develop chemical weapons, the MoD was called in to investigate.
Earlier this week (July 31st) workmen in Selby discovered what they thought was an unexploded grenade as they carried out work on constructing a beer garden at the Three Swans pub.
Police and the fire service were called in before army bomb disposal experts were summoned from Catterick, while rumours spread around the town that a rogue World War Two weapon had been found, according to the Goole Courier.
However, after investigations were carried out, the 'grenade' was actually revealed to be a hydraulic car pump.
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