MOSCOW (AP) — A Ukrainian lawmaker visited the rebel-held east on Friday to meet with Ukrainian prisoners there, a trip that irked many in Ukraine.

Nadiya Savchenko, a pilot who spent two years in a Russian prison before her release last year, visited a prison in the rebel-held city of Makiivka. Savchenko said on Facebook that her goal is to help free Ukrainian prisoners.

Following the visit, she told reporters that her goal is to arrange an "all for all" exchange of prisoners held by both sides.

Savchenko, who won a hero's status while in the Russian prison, has become a polarizing figure recently due to her criticism of the Ukrainian government and her calls for a dialogue with the Russia-backed rebels to end the fighting in eastern Ukraine. The violence has killed more than 9,800 people since April 2014.

Following her meeting in December with the rebel leaders in the Belarusian capital of Minsk, Savchenko's parliamentary faction dropped her from its ranks.

Ukraine's domestic security agency, the SBU, said Friday it will look into Savchenko's trip. Agency spokesman Oleksandr Tkachuk says Savchenko's trip is causing "bewilderment," according to the Interfax news agency.

A 2015 peace deal signed in Minsk has helped reduce fighting in eastern Ukraine, but a political settlement has stalled and clashes have continued.

Ertugrul Apakan, the chief of the Organization for Security and Cooperation in Europe's monitoring mission, criticized the rebels for seizing a drone Friday at gunpoint that monitors were attempting to launch in Yasynuvata, north of the main rebel stronghold of Donetsk. He said the rebels pointed their guns at the OSCE monitors, and one fired shots that landed near them

"Firing at unarmed civilian monitors is not only a direct threat to the lives of brave men and women doing their best to bring peace to Ukraine," Apakan said. "It is a direct challenge to the collective will of the 57 OSCE participating states, and to the Minsk agreements."