Ports across the country will soon experience operational overhauls to prevent another oil spill like the one in Dalian, Northeast China's Liaoning province.

In the wake of the accident, the Ministry of Transport, which oversees port operations, circulated a notice on Thursday urging local transport authorities to check on all ports handling dangerous chemicals by August.

Photo taken on July 19, 2010 shows the polluted sea area affected by oil leakage in Dalian, a coastal city in northeast China's Liaoning Province. Over 500 fishing boats Monday joined a massive oil spill clean-up operation underway off the coast of Dalian City, three days after pipelines exploded near the city's oil reserve base, one of China's largest. [Xinhua]

Special teams will be sent periodically to patrol at major oil and chemical ports to help detect hidden hazards, according to the notice.

Ports handling oil, liquefied chemicals and gases are required to carry out checkups on themselves every two years. They should also prepare an emergency response plan and carry out drills, the notice said.

The ministry said it also plans to establish a database of all ports that handle dangerous articles.

An explosion rocked an oil pipeline by 0.9 meters in diameter at 6:20 pm on July 16, triggering an adjacent smaller pipeline to explode near Dalian Xingang Port. Both pipelines are owned by China National Petroleum Corporation (CNPC).

The blasts unleashed a massive oil slick, and according to Monday's official survey results, about 366 square km of ocean were affected, including 52 square km that were polluted, and 12 square km that were classified as "severely" polluted.