Police units and the NPAS helicopter were called to Sirdar Road in Ipswich last night after receiving reports six or seven men had been acting suspiciously in the area.

Representatives for the force said one of the men was reported to have been holding a gun – sparking a large emergency response in the area.

They had only received one call about the reports, they said, but the National Police Air Service were informed shortly afterwards and sent the Boreham-based helicopter to assist.

A police spokeswoman said there was said to have been a house party in the area earlier in the evening and that detectives were sent to investigate at around 10.30pm on Friday.

The helicopter was spotted over the street at around 11pm but officers were stood down at 11.30pm after no trace of the men was found.

Anyone who may have seen suspicious activity in the area around the times specified above should call Suffolk police on 101 quoting CAD number 535 of Friday, June 16.