MOSCOW — A Russian court on Tuesday extended the arrest of Wall Street Journal reporter Evan Gershkovich by three months in a closed hearing emblematic of the secrecy that has marked the case against the first U.S. correspondent since the Cold War to be detained in Russia on spying charges.

Gershkovich, a 31-year-old American citizen, was ordered held until Aug. 30. He had been arrested in March on espionage charges on a reporting trip in Russia. He, his employer and the U.S. government have denied the charges.

Tuesday’s pretrial hearing wasn’t announced in advance, and the entire case has been wrapped in secrecy.

Russian authorities haven’t detailed what — if any — evidence they have gathered to support the espionage charges.

Various legal proceedings have been closed to the media. No details immediately emerged about whether Gershkovich attended Tuesday’s hearing or what was said. Tass said the session was closed because the reporter was accused of possession of “secret materials.”

One Russian news agency, Interfax, quoted a court official as saying Gershkovich’s parents — themselves Soviet emigres living in New Jersey — were visiting Moscow and had been admitted to the court building but not into Tuesday’s hearing. The U.S. State Department said at least one U.S. Embassy official attended the hearing.

Gershkovich’s arrest has rattled journalists in the country and drawn anger in the West.

The U.S. government has declared Gershkovich to be “wrongfully detained” and demanded his immediate release. He’s being held in Moscow’s Lefortovo prison.

U.S. Embassy officials were allowed to visit Gershkovich once in prison since his arrest in Yekaterinburg on March 29, but Russian authorities have denied two more recent requests to see him.

BORDER SKIRMISH

Russia’s military said Tuesday it quashed what appeared to be one of the most serious cross-border attacks from Ukraine since the war began, claiming to have killed more than 70 attackers in a battle that lasted around 24 hours.

Moscow blamed the raid that began Monday on Ukrainian military saboteurs. Kyiv portrayed it as an uprising against the Kremlin by Russian partisans. It was impossible to reconcile the two versions or say with certainty who was behind the attack or to ascertain its aims.

The battle — which took place in southwest Russia’s Belgorod region, about 45 miles north of the city of Kharkiv, in eastern Ukraine — was a fresh reminder of how Russia itself remains vulnerable to attack, along with Russian-occupied regions of Ukraine.

The region is a Russian military hub holding fuel and ammunition depots and was included in Russian President Vladimir Putin’s order last year to increase the state of readiness for attacks and improve defenses.

Kremlin spokesman Dmitry Peskov refused to say how many attackers were involved in the assault or comment on why efforts to put down the attackers took so long.

Such cross-border attacks embarrass the Kremlin and highlight the struggles it faces in its bogged-down invasion of Ukraine.

The Belgorod region, like the neighboring Bryansk region and other border areas, has witnessed sporadic spillover from the war.

Far from the 932-mile front line in southern and eastern Ukraine, Russian border towns and villages regularly come under shelling and drone attacks, but this week’s attack is the second in recent months that also appears to have involved an incursion by ground forces. Another difference from earlier cross-border attacks is that Russia’s effort to repel it continued into a second day for the first time.

Russian Defense Ministry spokesman Igor Konashenkov claimed local troops, air strikes and artillery routed the attackers.

“The remnants of the nationalists were driven back to the territory of Ukraine, where they continued to be hit by fire until they were completely eliminated,” Konashenkov said, without providing evidence. He did not mention any Russian casualties.

Russian forces destroyed four armored combat vehicles and five pickups the attackers used, he said. Local officials alleged the invaders also used drones and artillery.

The governor of the Belgorod region, Vyacheslav Gladkov, said the raid targeted the rural area around Graivoron, a town about 3 miles from the border. Twelve civilians were wounded in the attack, he said, and an older woman died during an evacuation.

Information for this article was contributed by staff writers and Susie Blann of The Associated Press.

 Gallery: Ukraine’s cross-border attack on Russia