Detectives appealing for witnesses after a spate of serious attacks on lone women around Hackney Marshes.

Two female joggers were approached by men as they ran through the marshes in east London on July 15.

The first victim, a woman aged in her 30s, was chased as she ran towards the red bridge on Hackney Marsh at about 10.15am. Fortunately her cries for help scared the man away and she was unharmed, police said.

Shortly afterwards, a second woman aged in her 20s was hit on the head by a man who tried to undress her near Lea Valley Riding Centre.

But the victim managed to get away and fled to a nearby home, Scotland Yard said.

Police believe the two attacks are linked. Detectives are hunting for a tall black man, aged in his 30s, who was riding a bike.

In a third attack just over a week later, a female cyclist was riding along Middlesex Filter Beds in Lea Valley when a man knocked her off her bike and punched her repeatedly in the face.

She suffered "serious facial injuries" in the attack on the evening of July 25, police said.

Detectives from the Met's Sexual Offences, Exploitation and Child Abuse Command are investigating all three attacks.

Local police officers have stepped up patrols on Hackney Marshes in order to protect the public.

Five men, aged 18, 20, 26, 34 and 50, have already been arrested and bailed in connection with the incidents, but police re-issued an appeal for information about the attacks today.

Detective Inspector Tracey Cormack, who is leading the investigation, said: "Specialist detectives are working around the clock to establish the full facts in relation to each incident.

"Patrols on the marshes and the local area have been increased. In the meantime I would urge women using the marshes and nearby open areas to continue to be vigilant and report any suspicious activity to the police."

Anyone with information can contact police on 101 or call Crimestoppers anonymously on 0800 555 111 or via crimestoppers-uk.org.