The deputy chairman of Turkey's ruling AK party says it is open to the idea of a referendum on controversial plans to redevelop Istanbul's Gezi Park, BBC News reported.

Huseyin Celik hoped the "gesture of goodwill" would clear the area, but said those who remained would "face the police".

Police treatment of people campaigning against the redevelopment triggered broader demonstrations from 31 May. Overnight, police in the capital Ankara fired tear gas to disperse protesters.

Senior European diplomats have expressed deep concern over Turkey's response to the protests. There is still no obvious way out of the impasse that has seen unrest in cities across the country for the past two weeks.

Demonstrators accuse Prime Minister Recep Tayyip Erdogan of trying to impose Islamic values on a secular state.