This is part one of a two-part series. Read part two. Kurdish music blasts through low-quality speakers inside our bus. Some of the passengers...

This is part one of a two-part series. Read part two.

Kurdish music blasts through low-quality speakers inside our bus. Some of the passengers clap to the rhythm while the older ones point to landmarks across the arid landscape, informing the younger and more inexperienced travelers the names of hills and villages passing by.

All of the travelers are peshmerga – Kurdish fighters – but the route they are taking will not end at the front line with Islamic State like elsewhere in Kurdistan. Instead these peshmerga are heading to another front line, one which the older fighters have not occupied for more than 20 years.

They’re heading to Iraq’s border with Iran.

All are exiles from Iranian Kurdistan and belong to the Kurdish Democratic Party of Iran, also known as the KDP-I.

The history of the KDP-I is, as typical here, complicated. The original KDP-I group formed as a democratic socialist and Kurdish nationalist party in 1945 in Mahabad, the capital of Iranian Kurdistan. The party predates the Iraqi Kurdish party, the KDP, by one year.

Although their politics are similar, the KDP-I differs from its Iraqi counterpart in that tribal links are not part of party politics.

The KDP-I set out to improve Kurdish rights in Iran and fought with Iranian forces for many years, even before the Iranian Revolution of 1979. Like all of Kurdistan, which is split between Syria, Turkey, Iraq and Iran, the Kurds have lived under the yoke of nations which divide their homeland.

These countries have human rights records which are not the most impeccable – and that’s definitely the case in Iranian Kurdistan, also known as Rojhelat by the Kurds.

A renewed insurgency took place in 1989 as a reaction to the assassination in Vienna of the KDP-I’s then leader, Abdul Rahman Ghassmlou, by suspected Iranian agents. A bloody fight between the KDP-I and the Iranian regime followed, involving deaths both inside Iran and other countries.

In July 1996, Iranian troops entered Iraqi Kurdistan, where the group had its base, displacing thousands of refugees and killing around 20 KDP-I members. On Aug. 4, 1996, the KDP-I announced it would cease cross-border raids in an effort to stop further incursions into Iraqi Kurdistan.

In the mid-2000s, the party split into two factions due to differences in strategy. Now there’s the KDPI (also known as PDKI) and … the KDP-I. Similar names for political groups are the norm over here. If that sounds strange, there are three different groups each named Komala also fighting Iran, all with slightly differing politics or strategies.

For the sake of ease we will call the other group the PDKI, though there have been recent talks to re-unite the two factions.

Fast forward to today and the KDP-I have moved back to its bases along the border with Iran in the Khandil Mountains – often regarded as the home base of the Kurdistan Workers’ Party, or PKK. Furthermore, the other parties are active in the area, including the PDKI. A potential rise in the tempo of operations against the Iranian regime is on the cards.

The root cause is that human rights abuses within Iran and Iranian Kurdistan are not showing any sign of stopping. The United Nations Human Rights Council reported that there were 753 executions in Iran in 2014, the majority of which were for crimes that do not meet international criteria for being “most serious” in nature. The KDP-I do not seek to split Rojhelat from Iran, just to give the Kurds there more rights and a fair chance.

In 2015, Iran is on track to surpass that amount having already carried out 694 executions between the start of 2015 and July 15 despite having elected moderate Hassan Rouhani as president in 2013.

The journey from the peshmerga’s main headquarters – an ex-Iraqi army fortress in Koya, some 50 kilometers to the west of Erbil — to the city of Choman is a long one. A few hours in, many of the travelers begin to snooze, their heads bobbing in motion to the movements of the vehicle. Kalashnikov rifles rest on any flat surface without baggage or sit propped between the knees of semi-conscious fighters.

The bus stops outside Choman in the pitch black night. Names are called and passengers transfer to other vehicles destined for various outposts along the Iranian border. We get into a 4×4 with Gen. Khalid, leader of the KDP-I’s peshmerga. His manner is gruff and professional, as one would expect of a soldier having fought in the mountains for many years before the group laid down its weapons in 1996.

Khalid calls out the names of villages along the road that winds to our destination. We are heading for a mountain camp some 10 kilometers from Iran, not far from where the Turkish air force has been bombing villages it claims are inhabited by PKK fighters.

Another day begins. The sun rises over a breathtaking mountain vista as peshmerga rise from sleeping bags and blankets. An elderly peshmerga boils water for tea on a metal stove. The mountains that make up the border with Iran are deceptively close. A lone peshmerga wanders over to a rocky crag to smoke a cigarette and keep watch as his comrades rise.

Scrub bushes and rocks make up the near landscape, and in the distance smoke lazily rises from part of the landscape as farmers burn dried foliage — a method often carried out to detonate leftover mines laid by the Iraqi army during the Iran-Iraq War three decades ago.

There’s a puff of smoke – an innocent looking mushroom cloud – a few kilometers away. A peshmerga points to it. It’s a mine detonation. The remoteness of the slowly dissipating smoke suggests that it was not set off by a person, one can only hope.

We were late arriving to the camp. The peshmerga showed us where to sleep, inside a large open tent made from burlap and loose weave material. The evening was cool because of the altitude, a breeze flapping the shelter in a rhythmic, soothing way.

Fighters rotate through various outposts, often spending up to 40 days in the mountains before heading back to the headquarters in Koya. To join the KDP-I, you must be at least 18 years old, and most of the new peshmerga first arrive at this camp.

With new – and often very young — peshmerga coming in from Iranian Kurdistan, the KDP-I puts the new fighters through a probationary period to weed out Iranian spies.

Even though the older generation may personally know some of the young fighters’ families, they still watch them. Once the new recruits prove themselves, the fighters slowly rotate forward to positions closer to Iran. The most experienced and trusted peshmerga will cross the frontier, to operate inside the borders of their homeland.

One of the oldest peshmerga is a 61-year-old veteran named Sufi. He carries a Kalashnikov taken from an Iranian soldier 21 years ago and walks with the aid of a stick – the result of a beating by Iranian prison guards during the six years he spent in incarceration, 15 months of which were spent in solitary.

Despite his damaged leg, he still manages to climb hills.

Just down the hill from our camp is the headquarters where Khalid commands his troops. The morning routine is in full swing here. Some peshmerga cook breakfast and boil tea, while others prepare equipment. A small group of fighters construct a bunker from rocks to create a more permanent emplacement.

The peshmerga have positioned their headquarters so they can watch down onto a path that serves as a major route for refugees. The genuine refugees passing through the area are OK, but the peshmerga want to ensure that slave laborers do not pass through. Slavery is something they disagree with and want to halt.

“This is a command and control center,” Khalid says. “Yesterday we sent a large amount of peshmerga inside of Iran. The orders came from here, it is from here we command everything.”

It’s a strategic location for the KDP-I. Looking around, it’s easy to understand why. Small narrow tracks populate the hills, which are sometimes hard for a 4×4 to traverse. Moving a large force through the area on foot would be difficult, let alone armored vehicles that move slowly and are vulnerable to ambush. And that’s before taking the numerous minefields into account.

The Iranian military invaded this mountainous region during the Iran-Iraq War, but failed to conquer it. “The Iranians tried to take place for years and they couldn’t,” Khalid says.

Although the KDP-I have returned to the area, and have sent fighters into Iran, the group is not seeking to directly engage with the Iranian forces, for now at least. However, it did skirmish in September with a pro-government militia in the Kurdish-Iranian town of Shino.

“We do everything we can to avoid physical contact with the regime,” Khalid says. “We do not get in conflict with them. The main objective is to be in our country to meet our people, to meet our agents, to meet our political partners, to spread our political ideologies so people can know what it is we are fighting for.”

Some of the other Iranian-Kurdish parties have declared war on the regime, including the PDKI, but beyond the recent firefight the most Khalid’s group has done for now is move weapons across the border. “This is where our people are, where our families are,” Khalid adds.

Contrary to what one would expect, the group’s goals are not to separate Rojhelat from Iran, but to gain more freedom for the Kurds – a different outlook than factions in Iraqi Kurdistan, where most people support and talk openly of independence from Baghdad.

The mobilization of the KDP-I and other groups have nonetheless provoked Tehran to react. Two months ago, the Iranian military had few troops opposite the border facing Iraqi Kurdistan.

Recently, Rear Adm. Ali Shamkhani, the secretary of Iran’s Supreme National Security Council, appeared on Iranian television to denounce the work of the KDP-I, stating that it was provoking war with Iran. Since then, Iran has moved large amounts of troops, including 100 tanks, Katyusha rocket systems and other heavy weapons closer to the border in an attempt to stop any incursions.

“We know our presence is provoking a lot of reactions,” Khalid admits.

Even on the Iraqi side of the border there have been problems. “The PKK have had some issues with the PDKI, which is the group that we split from some years ago,” Khalid says.

In May 2015, the PKK clashed with PDKI forces after the latter established bases in the border regions of the Khandil Mountains – an area that the PKK has held since the anti-Iranian rebels left the area years ago. Local media reported that two Iranian-Kurdish fighters died in the fight.

Khalid says the KDP-I has avoided conflict with the PKK, though both groups are near each other. There are only a few PKK fighters in this immediate area, though Turkish air strikes are visible from the KDP-I’s positions.

Khalid leaves for a meeting and we make our way back to the position where we slept the night before. The area around the two camps is strewn with unexploded ordnance of different types – detritus of the Iran-Iraq War. Fighters have cleared paths around both camps, but still warned us about wandering.

Back at the tent, peshmerga play chess, although with different rules than the ones I’m familiar with in the West. Their version is played at a much faster pace, and many of the moves seem democratic, with different peshmerga agreeing and disagreeing with the positioning of the pieces.

Joining in with the fighters playing chess is Ryan O’Leary. He is the exception to one of the rules that the KDP-I have had in place for many years. Although dressed in the traditional Kurdish garb, he’s not an Iranian Kurd, but an American, U.S. Army veteran serving as a foreign volunteer.

Having served in the infantry for 11 years, O’Leary’s past career includes operational tours of Iraq and Afghanistan. Like many western volunteers, he originally came out to the region to help fight Islamic State, but after meeting with the leadership of the KDP-I, he decided to try out for this group instead.

Putting the chess games aside for awhile, O’Leary takes us for a walk to a nearby ridgeline. We pass a former KDP-I position that is not presently in use, though the Kurdish flag still flies over the top. Shell casings from 23-millimeter guns are strewn about on the ground.

The fighters say the rocky area in front of the emplacement is mined, although there’s no familiar red warning triangles. Behind the position is a sheer face leading to a slope. O’Leary points down the slope, yet another minefield, but this time marked out to ensure no one walks too close.

There is litter from past wars all over the place. The KDP-I discovered a 122-millimeter Katyusha rocket next to another position. There’s still a debate over what to do with it — to pull it out or blow it up in place. O’Leary says he dealt with similar munitions in Afghanistan. He’s in favor of somehow finding enough rope to pull it out of the ground.

Looking down, there’s a smuggling route that heads across the Iranian border. Iran shut the route so the outpost lies dormant, but the fighters may put it back into operation if the passage opens up again.

Back at the tent, some of the fighters who we saw on the bus stop by for chai. “I left home to become a peshmerga,” Kowsa says.

Kowsa is an Iranian Kurd from Mahabad – the site of recent riots after a Kurdish hotel worker fell to her death after an alleged rape attempt. Kowsa explains that women’s rights are limited in Iran and being both Kurdish and female means she gets a doubly bad life.

In 2014, Iran imposed further restrictions on women’s rights, and convicted an Iranian-British woman of “propaganda against the state” after a protest over a ban on women watching men’s volleyball matches.

Now working as a teacher in the KDP-I’s education department, Kowsa’s parents opposed her joining the peshmerga because they were concerned for her safety. The Iranian government was also opposed, so much so that they asked her to become a spy for them — she said no.

Even if she went back now there could be ramifications, “Sometimes people who go back or hand themselves in are given drugs [by the Iranians],” she says.

The KDP-I peshmerga say they have at least one fighter who was given opiates by the regime in an effort to get him addicted. He came to Iraqi Kurdistan and went cold turkey with the group.

“Life over here is not bad, being peshmerga is good, because we are free,” Kowsha says.

The night falls quickly in the mountains. With no moon, the darkness hastily envelopes the outpost. A Kurdish flag flutters in the evening breeze, and some fighters pull guard duty while others cover themselves with blankets and settle in for the night. Tomorrow we will set out to visit some of the smugglers who operate in the mountains.