A quarter of the ground forces Russia used to invade Ukraine are now “combat ineffective,” according to the UK’s Ministry of Defence.

“Some of Russia’s most elite units, including the VDV Airborne Forces, have suffered the highest levels of attrition. It will probably take years for Russia to reconstitute these forces,” the ministry wrote in an update posted to Twitter on Monday.

The ministry added that Russia committed 65% of its ground forces – or about 120 battalions – to the invasion, yet has struggled to achieve any of its short-term goals.

As frustrations mount within the Russian military, they have relied increasingly on civilian attacks.

On Monday, Ukrainians stranded in Mariupol were finally able to escape the war-torn region. The Associated Press reports:

People fleeing besieged Mariupol described weeks of bombardment and deprivation as they arrived Monday in Ukrainian-held territory, where officials and relief workers anxiously awaited the first group of civilians evacuated from the steel plant that is the last stronghold of Ukrainian fighters in the devastated port city.

Video posted online Sunday by Ukrainian forces showed elderly women and mothers with small children climbing over a steep pile of rubble from the sprawling Azovstal steel mill and boarding a bus.

More than 100 civilians from the bombed-out plant were expected to arrive in Zaporizhzhia, about 140 miles (230 kilometers) northwest of Mariupol, on Monday, Ukrainian President Volodymyr Zelenskyy said.

“Today, for the first time in all the days of the war, this vitally needed green corridor has started working,” he said Sunday in a video message.

Meanwhile, the Ukraine military continues to make strategic gains against Russian forces. From The Wall Street Journal:

Ukraine on Monday said it sank two Russian naval vessels in the Black Sea with drone strikes, as explosions rang out once again in Russia’s border region of Belgorod and heavy fighting continued in eastern Ukraine.

Ukraine released video footage of what it said were Bayraktar TB-2 armed drones hitting the two Raptor-class patrol boats at 4.51 a.m. Monday near Snake Island, a Ukrainian island that Russian forces captured on the first day of the war on Feb. 24. Both boats appeared to be hit, but it wasn’t clear whether they had sunk.

Ukraine’s military said in recent days that it carried out several airstrikes on the strategic island, located 22 miles off the Ukrainian coast southwest of Odessa, destroying the air-defense system and other heavy weapons of the Russian military unit that occupies it. The two boats in the area, each capable of carrying 20 Marines in addition to three crew members, were likely to be carrying reinforcements and resupplies.

The Journal adds:

Taking the fight to the enemy by putting pressure on Russian supply lines inside Russia itself seems to have become a key part of Ukraine’s effort to repel the Russian offensive. Russian forces on Monday continued pressing into eastern Ukraine’s Donbas region, with heavy fighting north of the town of Slovyansk.

Ukrainian officials said that in recent days they carried out a series of strikes on Russian forward bases in the Izyum area north of Slovyansk, killing senior commanders including a general. While this claim couldn’t be independently confirmed, drone footage released by Ukrainian volunteers working with the military on Monday showed a series of precision strikes on a large grouping of Russian armor south of Izyum.

The New York Times reports on other key updates:

Speaker Nancy Pelosi, days after becoming the highest-ranking U.S. official to visit Kyiv, met with Poland’s president in Warsaw on Monday and said that Russia’s invasion of Ukraine should be punished by the “strongest possible military response, the strongest sanctions,” despite Moscow’s threats of retaliation against the West.

Although the Biden administration has ruled out direct U.S. military intervention in the war, the Senate is expected this week to take up President Biden’s request for an additional $33 billion in military aid for Ukraine — a significant escalation of American support that would put the United States on track to spend as much this year to help Ukraine as it did each year fighting the war in Afghanistan.