Nigeria, April 9 -- Several Iranian cities were jolted by explosions and military activity early Thursday, raising fresh concerns despite a recently announced ceasefire between the United States and Iran.

Witnesses reported blasts in Karaj, Ahvaz, Shiraz and other locations across the country. In Karaj, located in Alborz province west of Tehran, residents said three projectiles were seen over the Azimiyeh district before an explosion at dawn.

Additional blasts were heard in Mehrshahr at about 2:28 a.m., followed by further explosions around 3:45 a.m. in both Mehrshahr and Mohammadshahr.

In Ahvaz, the main city in oil-rich Khuzestan province, two strong explosions were reported at approximately 3:11 a.m. and 3:13 a.m., according to witn...