Egyptian authorities have detained an Australian journalist and an American student on suspicion they had distributed cash to workers and incited them to take part in a strike demanding an end to army rule, the state news agency said.
They were detained on Saturday along with their Egyptian translator and a local labour activist in the industrial city of Al Mahalla AlKubra north of Cairo.
They were referred to the prosecutor general for investigation, the agency said. It identified the American student as Derek Ludovici and the Australian journalist as Austin Mackell.
The labour activist was named as Kamal El-Fayoumi.
"Our car got rocked and beaten against the glass...got called a whore and all sorts of things. Police escorted us to station," Aliya Alwy, the Egyptian translator, posted on her Twitter account before their detention.
"Charges brought against (us) of inciting protest and vandalism. Witnesses have been produced to confirm it."
The Australian Foreign Ministry said an Australian national was detained in Mahalla and that the embassy in Cairo was seeking advice from Egyptian police on possible charges arising from the arrest.
The ministry did not confirm the name of the detainee.
"Consular officials from the Australian embassy in Cairo have spoken to the man ... He has confirmed he is being treated appropriately by local police authorities," the Australian Foreign Ministry said in a statement.
The four detainees were transferred to military intelligence headquarters in the nearby city of Tanta, translator Alwy said.
Accusations of alleged foreign meddling in Egyptian politics have started to gain pace in recent weeks.
The authorities in Cairo are prosecuting 43 foreign and Egyptian activists, including around 20 Americans, who had worked for pro-democracy groups including U.S.-based organisations.
The charges levelled against the pro-democracy activists include working for organisations not properly registered in Egypt and illegally receiving foreign funds.