KYIV, Ukraine, Aug 28, 2025 (BSS/AFP) - Powerful explosions were heard by AFP journalists in Kyiv on Thursday, as Ukrainian officials warned of a "massive" Russian attack on the capital.

The explosions illuminated the night sky above the city, leaving behind a column of smoke, an AFP journalist said. At least one missile appeared to be shot down.

Red tracer bullets sailed through the sky in an effort to intercept drones above the city centre, according to the journalist.

Mayor Vitali Klitschko said on Telegram that a "massive attack on the capital" was underway, with four people wounded so far.

Air defence forces were operating in the city, he said, urging residents to remain in shelters.

An AFP journalist witnessed around 100 people taking refuge in a subway station, with some lying in sleeping bags and others holding their pets.

Three other young people were seen anxiously waiting out the bombardment in an underpass.

Emergency services were working in Darnytsky, Dniprovsky and Shevchenkivsky districts, with initial reports indicating damage to some residential buildings, the mayor said.

Diplomatic efforts to end the war have accelerated in recent weeks following meetings between US President Donald Trump and his Russian and Ukrainian counterparts.

But there has been little tangible progress since then, with Moscow and Kyiv blaming each other for the impasse.