PESHAWAR, Jan 29: The Kohat tunnel has been closed for goods transport for indefinite period after a powerful blast late Friday night caused severe damage to its structure, said an official of the National Highway Authority.

Mr Omarzai said that goods transport, including trucks and trailers, were stopped from passing through the Kohat tunnel due to security reasons. The goods transport traffic has been diverted to alternative route passing through Kotal Pass.

Officials said that three people were killed and 15 others injured in the blast on Friday night.

Spokesman for the Rescue 1122 Aruj Sherazi told Dawn on Saturday that three bodies and five wounded persons were shifted to Lady Reading Hospital, Peshawar. An Afghan national identified as Islamabad was also among the dead, he said.

Mr Sherazi said that some of the injured were also taken to the hospitals in Kohat and debris was being removed from the tunnel.

Quoting an unnamed security officer, the National Highway Authority officials said that an oil tanker coming from Kohat side exploded at the tunnel's exit towards Peshawar at about 11.30pm on Friday. Reports said that the explosive device was planted in the oil tanker which caused a big blast.

According to unconfirmed reports, a second blast was heard on the Kohat side of the tunnel. An official said earlier that security forces had sealed the tunnel and the NHA engineers were not allowed to conduct examination of the structure.

“The NHA does not have the first-hand information and we have been told that explosion caused major damage to the infrastructure,” the official said, adding that the tunnel's structure was very strong but still expert analysis on any damage would be needed.

Contingents of Chitral Scouts have been deployed for the security of 1.9 kilometer long tunnel, which is also known as Pak-Japan Friendship Tunnel. The passageway was constructed with the financial and technical assistance of the Japanese government in 2003.

Militants had stormed the tunnel in January 2008 and carried out several blasts. During military operation in Darra Adamkhel the tunnel remained closed to traffic during night time. However, the authorities allowed night traffic through the tunnel about two months ago.