BEIJING (AP) — Emergency teams with helicopters rescued 34 workers Wednesday from an oil drilling platform that was leaning dangerously in the East China Sea after a storm, and searched for two others still missing, officials said.

The No. 3 drilling platform in the Shengli oil field, operated by Sinopec, Asia's largest refiner by capacity, started tilting over Tuesday, causing four workers to fall into the water and trapping 32 of them on the platform, the Transport Ministry said in a statement on its website.

Rescue helicopters were dispatched to the site from the coastal city of Dalian at around 6 a.m. local time, the ministry said.

The platform was tilting at a 45 degree angle to the sea, around five nautical miles (nine kilometers) from the coast, where the water is 23 feet (seven meters) deep, the official Xinhua News Agency said.

A typhoon caused the platform to tilt, said a man surnamed Sun from the Shengli Oil Management Bureau of Sinopec, also known as China Petroleum & Chemical Corp., in Dongying in Shandong province.

Sun said winds were blowing at up to 55 miles per hour (24.4 meters per second), causing 13-foot (four-meter) waves.