NATO Secretary-General Jens Stoltenberg said Tuesday that the military organization will send 700 more troops to northern Kosovo to help quell violent protests after clashes with ethnic Serbs there left 30 international soldiers wounded.

“We have decided to deploy 700 more troops from the operational reserve force for Western Balkans,” Stoltenberg told reporters in Oslo, after talks with Norwegian Prime Minister Jonas Gahr Store.

He said that NATO would also “put an additional battalion of reserve forces on high readiness so they can also be deployed if needed. These are prudent steps.” A battalion typically ranges from 300 to around 1,000 troops. The NATO-led peacekeeping mission, KFOR, currently consists of almost 3,800 troops.

Earlier Tuesday, KFOR peacekeepers used metal fences and barbed wire barriers to beef up positions in a hot-spot northern town.

The troops sealed off the municipality building in Zvecan where unrest on Monday sent tensions soaring, raising fears of instability and flareup in the Balkan hotspot amid increased Western efforts to resolve a long-simmering dispute.

Kosovo is a former province of Serbia whose 2008 declaration of independence Belgrade does not recognize. Ethnic Albanians make up most of the population, but Kosovo has a restive Serb minority in the north of the country bordering Serbia.

Stoltenberg condemned the violence, saying that “such attacks are unacceptable and must stop.” He warned that NATO troops “will take all necessary actions to maintain a safe and secure environment for all citizens in Kosovo.”

He urged both sides to take steps to deescalate, refrain from “further irresponsible behavior,” and to return to EU-backed talks on improving relations.

The United States and most European Union nations have recognized Kosovo’s independence from Serbia while Russia and China have sided with Belgrade. China on Tuesday expressed its support for Serbia’s efforts to “safeguard its sovereignty and territorial integrity” and Moscow has repeatedly criticized Western policies in the dispute.

Tensions first increased over the past weekend, after ethnic Albanian officials elected in votes overwhelmingly boycotted by Serbs entered municipal buildings.

When the Serbs tried to block them, Kosovo police fired tear gas to disperse the crowd.

In response, Serbia put the country’s military on the highest state of alert and sent more troops to the border with Kosovo. The Serbs protested again on Monday, insisting both ethnic Albanian mayors and Kosovo police must leave northern Kosovo.

The confrontations worsened when Serbs attempted to enter the municipal offices in Zvecan, 45 kilometers (28 miles) north of the capital Pristina.

They clashed first with Kosovo police and then with the international peacekeepers who deployed in Zvecan.

The flareup has triggered a flurry of international efforts to calm the situation.

The United States and the EU recently have stepped up efforts to negotiate an agreement between Serbia and Kosovo, fearing instability as Russia’s war rages in Ukraine. The EU has made it clear to both Serbia and Kosovo that they must normalize relations if they’re to make any progress toward joining the bloc.

“We have too much violence in Europe already today. We cannot afford another conflict,” the EU’s foreign policy chief, Josep Borrell, told reporters in Brussels on Tuesday.

He urged Belgrade and Pristina to “urgently take measures to de-escalate tensions immediately and unconditionally.” As a first step, he said, Kosovo police should suspend the operation focusing on municipal buildings in the north and violent protesters should “stand down.”

In response to recent unrest, NATO has decided to increase its KFOR troops with the deployment of the Operational Reserve Forces (ORF) for the Western Balkans, a statement said, without specifying the number. Another unit will be on standby “to be ready to reinforce KFOR if necessary.”

“The deployment of additional NATO forces to Kosovo is a prudent measure to ensure that KFOR has the capabilities it needs to maintain security in accordance with our UN Security Council Mandate,” said Adm. Stuart B. Munsch, commander of Allied Joint Force Command Naples (JFC Naples).

A statement Tuesday by the multinational peacekeeping force known as KFOR said 30 soldiers — 11 Italians and 19 Hungarians — “sustained multiple injuries, including fractures and burns from improvised explosive incendiary devices.”

Three Hungarian soldiers were “wounded by the use of firearms,” but their injuries were not life-threatening, the statement added.

Serb officials said 52 people were injured, including three seriously. Four protesters were detained, according to the Kosovo police.

“Both parties need to take full responsibility for what happened and prevent any further escalation, rather than hide behind false narratives,” said KFOR commander Maj.-Gen. Angelo Michele Ristuccia.

Belgrade and Pristina have blamed each other for the escalation.

The diplomatic pace increased. Ambassadors from the so-called Quint countries — France, Germany, Italy, the United Kingdom and the U.S. — met with Kosovo PM Kurti in Pristina on Monday and Serbian President Aleksandar Vucic in Belgrade on Tuesday.

Vucic later also met with the ambassadors in Serbia of Russia and China.

In a statement from his office, Vucic expressed “immense dissatisfaction and strong concern” over what he described as international “tolerance” of Kurti’s actions that fueled violence against Serbs.

Urgent measures to guarantee the security of the Serbs in Kosovo are a precondition for any future talks, Vucic insisted.

Kurti has thanked KFOR troops for “valiant action to preserve peace in the face of violent extremism.”

“The border between Kosovo and Serbia is one of those dangerous places where a spark could set off a fire,” said Italian Defense Minister Guido Crosetto.

Russia and China both have sharply criticized Western backing for Kosovo’s independence. Russia’s President Vladimir Putin often has cited the “precedent” of NATO bombardment of Serbia in 1999 to justify his unlawful annexation of parts of Ukraine.

China, which has established close economic ties with Belgrade through its foreign investments, blamed the violence on a failure to respect Serbian political rights.

“We oppose unilateral actions by the Provisional Institutions of Self-Government of Kosovo,” Foreign Ministry spokesperson Mao Ning said in Beijing.

The conflict in Kosovo erupted in 1998 when separatist ethnic Albanians rebelled against Serbia’s rule, and Serbia responded with a brutal crackdown. About 13,000 people, mostly ethnic Albanians, died.

NATO’s military intervention in 1999 eventually forced Serbia to pull out of the territory and paved the way for the establishment of the KFOR peacekeeping mission.

(AP)