"The trucks cannot be released as they are not carrying exemption papers," customs commissioner Dharam Pal Singh told AFP. "They do not even have any documents to show that this is a government-to-government effort."

Singh said only the finance ministry could clear the goods and that the concerned authorities had been informed.

The trucks are carrying medicines, soaps, clothes, tents, milk powder, tooth pastes and water purification equipment collected by school children, said Nicolien De Kron, a school girl, who is part of the delegation accompanying the vehicles.

She said the material was meant for tsunami survivors in southern India's Tamil Nadu state where at least 10,000 people died when the killer waves struck last December.

The group began its journey on January 14 and reached India after travelling 10,000 kilometres (6,200 miles) and crossing Germany, Austria, Hungary, Romania, Bulgaria, Turkey, Iran and Pakistan, De Kron said.

"In all the other countries, no one stopped us. It is only here that we are facing this problem," De Kron said.

"Before starting off, we involved nearly 20,000 children to collect the relief material from various parts of Holland," she said.