Surrey's security staff and the county's stewards began to search the ground and its immediate environs in a bid to find the culprit. There are no reported injuries.
After an unusual incident at The Oval cricket ground during the county match between Surrey and Middlesex, the officials chose to suspend the play for the day on Thursday.
During the final session of the County Championship fixture, a crossbow bolt - fired from outside the ground - landed in the centre of the pitch.
The arrow, which The Guardian reports had "a metal tip," was brought to the attention of umpires who informed players to leave the field.
"Police were made aware on Thursday, 31 August of reports that an arrow or crossbow bolt had been loosed into the Oval Cricket ground", said a Metropolitan Police statement.More news: Notorious Trump supporter David Clarke steps down as Milwaukee County's sheriff
More news: Trump pitches 'biggest-ever' tax overhaul while in Missouri
More news: Chelsea midfielder Bakayoko on Drinkwater talk: He doesn't scare me!
A spokesman for Surrey said: "We were about to bowl the next ball and the arrow appeared two pitches to the side of the pitch we're playing on at the moment".
Oliver Florence, a reporter for our sister title Get Surrey, is at the scene and said he saw armed officers enter the venue.
Players alerted the umpires and play was suspended. The ground is being evacuated.
More than 1,000 fans were advised to take cover and evacuated from the central London cricket ground after the projectile fell to the ground.
It was later abandoned with the game ending in a draw.