ISTANBUL (AP) — Turkey’s government on Wednesday offered a first concrete gesture aimed at ending nearly two weeks of street protests, proposing a referendum on a development project in Istanbul that triggered demonstrations that have become the biggest challenge to Prime Minister Recep Tayyip Erdogan’s 10-year tenure.
Despite the offer, protesters continued to converge on Istanbul’s Taksim Squire, the epicenter of repeated clashes between riot police firing tear gas, water cannons and rubber bullets, and stone-throwing youths for 13 days — an early sign that the proposal hadn’t defused the demonstrators’ concerns.
Word of such a referendum came after Erdogan hosted talks with a small group of activists. Many civil society groups behind the protests boycotted those talks in the capital, Ankara, saying they weren’t invited and that the attendees didn’t represent them.
The discussion was the first sign that Erdogan was looking for an exit from the showdown, and came hours after some European leaders expressed concern about strong-arm Turkish police tactics and hopes that the prime minister would soften his stance.
After the meeting, a spokesman for Erdogan’s Islamic-rooted party announced the referendum proposal at a news conference.
In a more defiant note, Justice and Development party spokesman Huseyin Celik said the ongoing sit-in in Gezi Park, next to the square, would not be allowed to continue ‘‘until doomsday’’ — in a sign that authorities’ patience is running out.
But Celik also quoted Erdogan as telling the activists he met that police would be investigated and any found to have used excessive force against protesters would be punished.
The protests erupted May 31 after a violent police crackdown on a peaceful sit-in by activists objecting to a development project replacing Gezi Park with a replica Ottoman-era barracks. They then spread to dozens of cities, and have attracted tens of thousands of people each night.
The proposed referendum would be over the development project, Celik said. But he said it would exclude the planned demolition of a cultural center that the protesters also oppose. Celik said the center was in an earthquake-prone area and needed to come down.
Erdogan has become the centerpiece of the protesters’ ire over his alleged authoritarian streak. So a referendum would be a political gamble that the government would win the vote and the demonstrators would go home.
‘‘The most concrete result of the meeting was this: we can take this issue to the people of Istanbul in a referendum. We can ask the people of Istanbul if they want it (the barracks),’’ Celik said. ‘‘We will ask them: ‘Do you accept what’s going on, do you want it or not?’’’
In a sign of the protesters’ suspicion about Erdogan, several in Gezi Park said they thought the government would rig the referendum’s result — or balk at holding it at all.
‘‘I don’t think anything changed with that,’’ said protester Hatice Yamak, of the referendum plan. ‘‘We don’t think he will do it — I think he’s lying.’’
Across Turkey, thousands of demonstrators have been mobilizing nearly every night — mostly in Istanbul in recent days. As if to let the referendum proposal sink in, the Istanbul governor, Huseyin Avni Mutlu, tweeted that riot police would not enter Gezi Park on Wednesday.
A union leader who met earlier with Erdogan suggested the government was preparing a final crackdown to quash the protests. Bendevi Palandoken of Konfederation told The Associated Press that Erdogan ‘‘told me that the protests will end in 24 hours, and the police intervention will comply with European Union standards.’’
‘‘Erdogan also told me he would meet with the youngsters today and will learn their complaints,’’ Bendevi said, referring to Wednesday’s talks. A spokesman for the prime minister could not be immediately reached for comment, and the Interior Ministry declined to comment.
British Prime Minister David Cameron and EU foreign policy chief Catherine Ashton were among the Western leaders who expressed concern about a crackdown overnight into Wednesday, during which riot police fired tear gas, water cannons and rubber bullets to disperse pockets of stone-throwing youths among the mostly peaceful protesters.
Turkey’s Human Rights Foundation said Istanbul prosecutors were investigating allegations of excessive use of police force during the protests.
The foundation said 620 people, including a 1-year-old baby, were injured during the police crackdown early Wednesday. Police detained around 70 people during the incidents. Prior to this, activists reported that 5,000 people had been injured or seriously affected by the tear gas and four people have died in the protests.
Germany’s government was ‘‘following the news from Turkey with great preoccupation, especially the images of yesterday’s police action,’’ Chancellor Angela Merkel’s spokesman Steffen Seibert said Wednesday. ‘‘Now de-escalation is needed. Only an open dialogue can contribute to easing the situation.’’
A spokesman for the Canadian Broadcasting Corp. said police had detained two of its reporters covering the protests in Istanbul. The broadcaster was in contact with Sasa Petricic and Derek Stoffel, and they were in ‘‘good condition,’’ CBC spokesman Chuck Thompson said. Canadian Foreign Affairs Minister John Baird tweeted that he had called the Turkish ambassador to express his concerns.
The protests took a new flavor earlier Wednesday as thousands of black-robed lawyers stormed out of their courthouses to deride allegedly rough treatment of their colleagues detained by police a day earlier. Sema Aksoy, the deputy head of the Ankara lawyer’s association, said the lawyers were handcuffed and pulled over the ground. She called the police action an affront to Turkey’s judicial system.
‘‘Lawyers can’t be dragged on the ground!’’ the demonstrating lawyers shouted in rhythm as they marched out of an Istanbul courthouse. Riot police stood off to the side, shields at the ready.
The government, meanwhile, pressed ahead with uncertain efforts to defuse the protests.
President Abdullah Gul, seen by many as more moderate than Erdogan, said the government couldn’t tolerate more of the unrest that has disrupted daily life in Istanbul and beyond. He promised, however, that authorities would listen to protesters’ grievances.
‘‘I am hopeful that we will surmount this through democratic maturity,’’ Gul told reporters. ‘‘If they have objections, we need to hear them, enter into a dialogue.’’
Erdogan hosted 11 activists — including academics, students and artists — in his party’s offices in Ankara. Some leaders of civil society groups, including Greenpeace, said they would not participate because of an ‘‘environment of violence’’ in the country.
The activist group Taksim Solidarity, which includes academics and architects who oppose the development plan, said its members hadn’t been invited to the meeting with Erdogan and predicted it would yield no results.
‘‘As police violence continues mercilessly ... these meetings will in no way lead to a solution,’’ the group said in a statement. It again demanded that Gezi should remain a public park, abusive senior officials should be fired, and all detained protesters should be released.
Erdogan has said the protests and sit-ins are hurting Turkey’s image and economy, being orchestrated by extremists and ‘‘terrorists,’’ and must end immediately.
Keaten reported from Ankara. Suzan Fraser and Ezgi Akin in Ankara, Juergen Baetz in Berlin, and Rob Gillies in Toronto contributed to this report.