Updated

The city council in Donetsk says no deaths overnight, one of the quietest nights recently in eastern Ukraine.

However, Col. Andriy Lysenko, spokesman for Ukraine's National Security and Defense Council, told journalists on Thursday that one emergency worker had been killed by fighting near Donetsk's airport. Combat has continued around Donetsk despite a formal cease-fire declaration.

The city council of Donetsk said in a statement published online that the situation in much of the city was calm although occasional explosions could still be heard in a neighborhood in the north, near the government-held airport.

Ukrainian President Petro Poroshenko traveled to the United States on Thursday to meet with Secretary of State John Kerry and address a joint session of Congress.