The large trench is seen in the most recent Sentinel-2 satellite pictures.
In preparation for a counterattack by Ukraine, the Russian military is building massive defensive fortifications that can be seen from space, according to satellite images published by the Ukrainian Centre for Journalistic Investigations.
Vladimir Putin's forces are building a huge trench across Ukraine's invaded region of Zaporizhzhia that is some 45 miles (72.42 kilometres) in length so far.
As reported by the correspondent of the Centre for Journalistic Investigations, the extreme points of the Russian fortified area in the west, discovered thanks to photographs from the Sentinel-2 satellite, are located in the vicinity of the village of Semenovka. This is about nine kilometres from the centre of Melitopol, which the occupation government of the Russian Federation in the region has designated as its capital.
A man-made gorge that connects a field outside the village of Marynivka to the fringes of the village of Semenivka is seen in the most recent photographs taken by the Sentinel-2 satellite.
Satellite data analysis reveals that this line of defence's construction started in early September 2022.
Approximately one-third of the Zaporizhzhia Oblast, which Russia annexed last year, is covered by the defensive trench.
Meanwhile, on Tuesday, the head of Russia's FSB security service accused Ukraine and the West of recruiting young Russians to stage armed attacks in their home country.
The accusation by security chief Alexander Bortnikov comes a week after President Vladimir Putin accused the West of helping Kyiv stage "terror attacks" in Russia while Moscow pursues its military offensive against Ukraine.
Moscow has cracked down on criticism of its campaign in Ukraine, with a growing number of treason cases and long prison sentences for social media dissent.
"In the conditions of Russia conducting the special military operation, Ukrainian special forces and their Western curators have launched an aggressive ideological indoctrination and recruitment of our citizens," Bortnikov told a meeting in Moscow of the National Anti-Terrorism Committee.
"Especially the younger generation, to involve them in sabotage, terrorist, and extremist activities," he added, according to a statement from the committee.
(With inputs from AFP)