BEIJING - Subway passengers in Beijing will have to face security check at three more stations starting Saturday as a new measure was launched to beef up subway security.

Previously, only personal belongings needed to be checked when passengers entered a subway station.

In January, Beijing Subway required that passengers should also go through security check at six stations, all near the Tian'anmen Square in central Beijing.

The security measure was expanded to three more stations -- two in the city's north and one in the west -- on Saturday, all far from the downtown area, according to the Beijing Subway.

Beijing is home to 21 million permanent residents. The city currently has 465 km of subway lines in operation, which carry 10 million passengers daily.

The new subway security measure comes as Beijing and the country at large are facing more severe challenges of violent terrorist attacks.

A terrorist bombing attack occurred at an open air market in Urumqi, capital of far west China's Xinjiang Uygur Autonomous Region, on Thursday, leaving 39 people dead and 94 others injured. That followed a string of violent attacks that shocked the country, including one at a train station in the southwestern city of Kunming in March and another one at Tian'anmen Square in Beijing in October last year.

Authorities in Beijing have launched several anti-terrorist drills over the past month, in a bid to tighten the capital's security.