Three people are injured after Russia says it accidentally bombed its own city.

A Russian warplane accidentally dropped a bomb on one of its own cities, the Russian Defense Ministry said on Friday. The blast, which videos showed hit near an apartment block, wounded three people and spread panic in a major city along the border with Ukraine.

Reports first came in on Thursday night that an explosion had ripped through central Belgorod, a southern Russian city of 400,000 just across the border with Ukraine. Widely circulated video footage showed a burst of smoke and flames near an intersection that cars were passing through, sending one parked vehicle twirling through the air.

Suspicion initially fell on Ukraine: Since the beginning of the war last year, the Russian authorities have blamed Kyiv for a string of covert attacks on railway bridges and other strategic targets in Belgorod. The attacks have put Belgorod on edge; some residents have said that they’re worried the Ukrainians might even invade.

But on Friday morning, the Russian Defense Ministry released a statement saying that the explosion was caused by “an accidental discharge of aviation ammunition” by a Russian fighter jet flying over Belgorod at around 10 p.m. on Thursday. The jet was identified as an Su-34, considered one of the most advanced Russian aircraft.

Vyacheslav Gladkov, the governor of the Belgorod region, said that three people had been injured, including one who suffered a concussion. The blast shook a nearby apartment building so badly that local authorities decided to evacuate it.

“Thank God no one died,” Mr. Gladkov said in a video posted on the Telegram social messaging app.

The Defense Ministry said the incident was under investigation.

Boris Rozhin, a pro-Russian military analyst and blogger, suggested in a post on Telegram that the accident could have been the result of a malfunction in a GPS guidance kit attached to a munition carried by the Su-34. Ukrainian officials and military analysts say that Moscow is using the kits in an effort to turn unguided munitions into cheap substitutes for precision aerial weapons.

The kits are still “raw” and can easily malfunction, possibly leading to accidents like the one in Belgorod, Mr. Rozhin wrote.