Russian attacks across Ukraine killed at least eight people and wounded several others as the United States increased diplomatic efforts to de-escalate the war.

Six people were killed in an attack on a farm in Kharkiv region, while two others died in attacks on Kyiv, including one near a damaged maternity hospital.

Ukraine said the assault involved 282 drones along with hypersonic and ballistic missiles, while Russia said it targeted Ukrainian military, logistics and telecommunications sites.

Poland and the Czech Republic deployed fighter aircraft to protect Polish airspace, Al-Jazeera has reported.

Polish officials described the incident as potential hybrid warfare, although responsibility had not been established and Russia has denied carrying out such attacks.