Migrant workers clashed with local police in two Indian states on Monday as frustration grows under lockdown restrictions.

In the city of Surat in Gujarat state, around 4,000 migrant workers — mostly from the states of Uttar Pradesh and Bihar — had gathered and were demanding that they be sent back home, said Ashok Munia, a senior Surat police official.

“For about two hours, we tried to make them understand that if their states give permission to receive them, we will send them across. But they were not listening,” said Munia.

The protest turned violent after local police were unable to pacify the crowd. They threw stones at police and were burning tires in the street, added Munia. Police used tear gas on the crowd and beat them back with batons in an attempt to control the situation.

In Bengaluru in the state of Karnataka, 1,200 migrant workers, primarily from the states of Bihar and Odisha, gathered on the outskirts of the city demanding trains be arranged to send them home, police sub-inspector, Y Mudharaja, said.

“They were striking and when we tried to calm them down they started pelting stones, I was hit on the head as well,” Mudharaja said.

The police commissioner and the state revenue minister arrived at the spot and addressed the workers after which they finally agreed to disperse, Mudharaja added.

Migrants stranded: India has been under a nationwide lockdown since March 25. That’s been an issue for the country’s millions of migrant workers, many of whom earn a daily wage rather than a salary.

According to government statistics, every year more than 9 million migrant workers move from India’s rural areas to large population centers to find work at construction sites or factories, sending money back to their home towns and villages.

But with those industries closed by the government lockdown, many have been left with little choice but to attempt the return journey home.