Russian troops are said to be gathering in large groups, allowing them to be targeted by drones and taken out by missiles: ISW

• Russian troops keep on gathering in groups, military bloggers said, according to a think tank. 
• War bloggers are said to be concerned that this allows them to be targeted by Ukrainian missiles.
• Ukraine is using drones and missiles for strikes amid intensifying Russian attacks. 

Russian commanders seem to be continuing to gather their troops in large groups, enabling Ukraine to target them with long-range missile strikes, according to a US think tank.

The Institute for the Study of War, on Wednesday, said that Ukraine had conducted another strike on a gathering of Russian troops in Donetsk Oblast, east Ukraine, sparking fury among Russian milbloggers.

"Russian milbloggers appear increasingly concerned that Ukrainian forces are able to exploit poor Russian operational security practices (such as large gatherings in near-rear areas under Ukrainian aerial reconnaissance) using well-timed and well-targeted HIMARS strikes, which continue to generate discontent in the Russian information space," it said.

The ISW said that an individual claiming to be from the Russian military had posted on Telegram that a Ukrainian missile had killed 19 soldiers, including the brigade commander and other senior officers. It injured 12 others in a strike at an awards ceremony on February 27, it added.

According to the report, commanders had ignored Ukrainian drone surveillance of the site and had gone ahead with the ceremony, the ISW said.

It's the latest in a series of similar strikes in which Ukraine has used precision-guided US-made HIMARS missiles to hit Russian troops gathering miles behind the front line.

The ISW noted that in the past week alone Ukraine has targeted a Russian training ground in Donetsk, in which 60 Russian troops were killed, and a training ground in Kherson Oblast, in which an unknown number of troops were killed, according to reports.

Ukraine has also used exploding drones to target groups of Russian troops and armored vehicles gathering to attempt to break through Ukrainian defensive lines.

The ISW said that Russian milbloggers, who have been an important source of independent information on the Russian military during the Ukraine war, believe that inept Russian commanders are to blame.

"One milblogger noted that 'these are no longer isolated mistakes,' and suggested that Ukraine is deliberately striking such gatherings of Russian personnel in a 'clinical" manner,'" said the ISW.

Airborne drones have transformed the nature of war in Ukraine, enabling comprehensive surveillance of the battlefield and making large gatherings of troops for attacks, training, or morale-boosting ceremonies increasingly dangerous.

Missiles given to the Ukraine by the West, such as HIMARS, have enabled Ukraine to hit Russian targets from up to 50 miles away.

Despite its skillful use of drones and other weapons, Ukraine is on the back foot, with an aid block by Republicans in the US Congress, meaning troops are experiencing serious ammunition shortages.

Russia's attempts to take advantage of the situation appear to be being hampered by the issues with poor command that have impacted its invasion since its earliest days.

Russia, earlier in February, made its most significant advance in the war for months when it seized control of the village of Avdiikva from Ukraine at a steep cost in casualties.