Unknown gunmen attacked a remote camp of a Chinese construction company Saturday in northwestern Afghanistan, causing no casualties, an official of the company told Xinhua Monday.

Chinese workers in the attacked camp of China Railway Shisiju Group Corporation had safely withdrawn to a major base 40 km away, said the official, who refused to be named.

According to the official, the militants launched a fierce attack against the walled camp in Duabi area of Badghis province at 9:23 p.m. local time on Saturday and Afghan policemen guarding the camp fought back.

After a fire exchange lasting about one and a half hours, the two sides stopped firing, but the gunmen refused to retreat.

At around 11:20 p.m., the militants were forced to flee as more policemen from a nearby police station arrived at the site.

When the clash occurred, there were 30 Chinese workers, who were building a local road, stationed in the camp, which was surrounded by thorny wire netting and entrenchment.

It is still unclear who were behind the attack and what was the motivation.

After receiving aid-seeking information from the camp during the conflict, the Chinese embassy in Afghanistan immediately contacted NATO troops keeping security here, who agreed to send NATO helicopters to the site if needed.

The embassy also urgently met with officials of the Afghan Foreign Ministry, asking the Afghan government to take measures to ensure the safety of the attacked Chinese workers and to find who were behind the assault.

This is the most severe attack against Chinese companies in Afghanistan since June, 2004.

Source: Xinhua