Indian authorities seized 90 kg of drugs worth $58 million at a port in the western state of Gujarat, police said, Reuters reported.

On Friday, a container was seized that arrived at the port of Pipawava at a time when India has stepped up vigilance on its western border to prevent drug smuggling from Iran and Afghanistan.

The container was filled with yarn, but the examination showed that the threads were soaked in a heroin derivative, after which they were dried and turned into bales, a state police spokesman told Reuters.

The heroin contained in the threads would have to be removed, the federal government said in a statement.

Police this week seized 56 kilos of heroin worth $37 million and arrested nine Pakistanis in a maritime operation. Authorities also seized 205.6 kg of heroin worth $188 million this month at the port of Kandla in Gujarat.

India accuses neighboring Pakistan of encouraging the drug mafia to network across the border, which Pakistan rejects.