DONETSK, Ukraine — Thirty pro-Russia insurgents and four government troops have been killed during operations to expunge anti-government forces around a key eastern city, Ukraine's interior minister reported today.

In the southwest, Kiev authorities also attempted to reassert control over the key Black Sea region of Odessa by appointing a new governor there.

Interior Minister Arsen Avakov gave the death toll on his Facebook page today, adding that 20 government troops were also injured during fighting in Slovyansk, a city of 125,000. It was not exactly clear when the deaths took place. Gun battles around the city Monday were the interim government's most ambitious effort to date to quell weeks of unrest in Ukraine's mainly Russian-speaking east.

Avakov said Monday about 800 pro-Russia forces in and around Slovyansk were deploying large-caliber weapons and mortars and there were injured on both sides.

By this morning, Ukrainian forces had taken hold of a key checkpoint north of the city, dealing a blow to insurgent lines of communication. The checkpoint had come under repeated attack since the government offensive began.

SEOUL, South Korea — A civilian diver involved in searches for dozens of missing people from a South Korean ferry disaster died today, as other divers helped by better weather and easing ocean currents were picking up efforts to retrieve bodies from the sunken ship.The Sewol carried 476 people, most of them students from a single high school, when it sank off South Korea’s southern coast on April 16. Only 174 survived, including 22 of the 29 crew members. The sinking left 260 people dead, with about 40 others still missing.Today, one civilian diver died at a hospital after becoming unconscious. The 53-year-old diver was reportedly pulled to the surface by fellow divers after losing communication.Divers have been working their way into the last three unopened rooms.