DAKAR, Senegal — A team of Al-Jazeera journalists was released late Monday after being detained for three days in eastern Niger, where they were held in a prison cell, according to a statement from the Qatar-owned network.

"An Al-Jazeera correspondent and her team have been finally released from a Niger jail after being held by authorities since Saturday," the statement said. "The four-person team was released late on Monday evening without charge to make (their) way back to the border."

Niger's government spokesman said the group was filming illegally, having entered the country with only a visa. Journalists in Niger are required to also apply for an authorization from the ministry of communication, said spokesman Marou Amadou, who is also the country's justice minister. He denied that the team had been held, saying only that their material was seized and inspected.

The Al-Jazeera statement did not say whether the crew got their material back.

Hasan Salim Patel, a spokesman in the network's media relations office, said the Al-Jazeera crew had just finished filming a story on refugees who have been flooding across the border from neighboring Nigeria, where security forces recently launched a military operation to flush out Islamic insurgents. Patel said the team was detained on Saturday after leaving the Niger town of Goure.

The team — correspondent Yvonne Ndege, camera operator Romuald Luyindula and producer Mohammed Abubakar, as well as driver Rabiu Abdullahi — were transferred to the district capital of Zinder.

"They were taken to Zinder for questioning by what they believe are intelligence services and interrogated for 10 hours," Patel wrote in an email. "They were again arrested around (3 p.m. GMT) Sunday, charged with espionage. A couple of hours later, denied any rights with passports, gear taken away and all personal belongings including shoes and jewelry. They were all put in shared holding cells, denied food and water."

On Sunday, they were taken for fingerprinting. They were able to see that their file read "espionage," though the evidence field had been left blank. Later in the day, they were told that they were free to go and were taken to the senior official who was supposed to return their passports. "Within an hour, the team was detained again, this time without any charges of explanation and their gear has been taken again," Patel said in the email.