Archeologists have started excavating tombs believed to be more than 1,200 years old in North China's Hebei province after they were exposed by a storm and a villager discovered them.

Zhang Jinqiang, resident in Zhengkou village of Huanghua city, noticed black bricks in a drainage canal to the east of the village after heavy rain washed away their covering of earth last week. The bricks were clearly different to those used nowadays in the area.

"I thought there might be something under the bricks," said Zhang, who took a shovel and dug nearby, finding a green-glazed bowl and a broken jar.

Zhang Baogang, curator of Huanghua's museum, told Xinhua that archaeologists have already found two small burial chambers and are expecting to find a whole cluster of tombs that should provide useful evidence of historic local customs.

"The bricks, bowl and jar indicate the tombs may date back to the Tang Dynasty (618 AD - 907 AD)," said Zhang.

Provincial history authorities said large-scale excavation of the site will start in early August.