The cargo plane seized Saturday in Thailand on suspicion of carrying North Korean weapons had reportedly transported North Korean freight via Bangkok multiple times.

According to a Thai police probe into the pilot and crew, the plane loaded the cargo in North Korea, left Pyongyang, and was to be refueled in Thailand and Sri Lanka before delivering the weapons to Ukraine.

The pilot and crew claim that they had no idea they were transporting weapons.

Meanwhile, a Thai court Monday extended by 12 days the detention of the pilot and crew to allow for further investigation into the case.