Police are appealing for witnesses following two reports of robbery in the Ferndale Road area of Swindon.
The first incident happened on Southbrook Street where around four people jumped out of bushes wearing balaclavas around 7.10am, frightening a woman.
She called the police straight away and the group ran off.
The second incident happened on Saturday morning at around 5.15am at an alleyway off Ferndale Road leading to the playpark.
A woman in her 20s was assaulted and robbed of her bag and phone.
Detective Inspector Eirin Martin said: “These are really concerning incidents where lone women are being targeted in the early hours of the morning.
“A cordon has been put in place on the access road to Ferndale Road Playground while we investigate what has happened and people will see more police and increased police presence in the area.
“I would urge everyone to be vigilant and to report anything suspicious to us no matter how minor as it may help us to find out who is carrying out these offences.
“Please look at your doorbell videos and CCTV from those times and dates and get in touch as soon as possible if you have any information that could help with our enquiries.”
If you have information that can help with our enquiries call 101 quoting reference number 54230103649.
