Latvia’s centre-right prime minister has resigned over her government’s handling of Ukrainian drones that strayed into Latvian territory from Russia, bringing down her coalition government months before elections due in October.

Evika Siliņa announced her resignation on Thursday, a day after the Progressives party, her left-leaning coalition partner, withdrew its support over her decision to fire the defence minister, Andris Sprūds, a Progressives member.

The Progressives’ move left Siliņa, who leads the centre-right New Unity party, without a ruling majority. Latvia’s president, Edgars Rinkēvičs, is due to meet all party representatives on Friday for talks on a new government.

Announcing her resignation, Siliņa said: “The most important thing for me is the wellbeing of Latvians and our country’s security … The brutal war waged by Russia in Ukraine has changed the security situation throughout Europe.”

Sprūds was forced to resign on Sunday after Siliņa said he had lost her trust and that of the public over the handling of incidents involving stray drones, suspected to be from Ukraine, that had crossed into Latvia.

In the most recent incident, on 7 May, two drones exploded at an oil storage facility. That “clearly demonstrates that the political leadership of the defence sector has failed to fulfil its promise of safe skies over our country”, Siliņa said on Sunday.

The head of the army said it had not detected the drones, flying in from Russia, for which Siliņa blamed Sprūds for not having overseen fast enough development of anti-drone systems.

Numerous Ukrainian drones have strayed from Russia into Latvia, Lithuania and Estonia since March. Government critics in Latvia say this reveals weaknesses in the country’s response to potential threats.

Ukraine’s foreign minister, Andrii Sybiha, said on Sunday the intrusions were “the result of Russian electronic warfare deliberately diverting Ukrainian drones from their targets in Russia”. Ukraine’s president, Volodymyr Zelenskyy, has offered to send experts to Latvia to help protect the skies.

Sprūds’s sacking prompted nine of his fellow Progressive party members to quit the coalition, alleging Siliņa had made him a scapegoat. That left the government with 41 seats in the 100-seat parliament and facing the prospect of losing a confidence vote.

As Russia’s war on Ukraine continued to affect the region, Hungary summoned Moscow’s ambassador on Thursday over a Russian drone attack on Ukraine that killed at least six people and prompted Poland to scramble fighter jets.

Hungary’s new prime minister, Péter Magyar, in a stark change of tone from his Moscow-friendly predecessor, Viktor Orbán, said his foreign minister, Anita Orbán, would express to the ambassador Hungary’s “strong condemnation” of the Russian attack. He said the foreign minister would also ask “when Russia and Vladimir Putin plan to finally end this bloody war that began more than four years ago”.

Zelenskyy said Hungary’s response sent an “important message”. Under the previous far-right government, Budapest had repeatedly sought to block military aid for Ukraine and sanctions against Russia.

While Poland scrambled fighter jets, Slovakia closed its border with Ukraine “for security reasons”. Moldova, meanwhile, said a Russian drone had crossed into its airspace and flown for about 180 miles.