* Protesters say their land seized to build factories

* Government wants to industrialise agrarian nation

* Demonstrations have broadened to political complaints (Adds U.S. citizen killed in unrest, another factory damaged)

By Aaron Maasho

ADDIS ABABA, Oct 5 (Reuters) - A U.S. citizen was killed and foreign-owned factories and equipment damaged during a wave of protests over land and political rights in Ethiopia this week.

The U.S. Embassy said the American woman was killed on Tuesday when stones were hurled at her vehicle on the outskirts of Addis Ababa, where residents said crowds have attacked other vehicles since a stampede at a weekend protest killed at least 55 people.

The weekend crush took place when police fired teargas and shots in the air to disperse anti-government demonstrations during a festival in the Oromiya region, south of the capital.

The embassy did not give further details or a precise location for the incident.

Oromiya has been a focus for demonstrations by locals who say land has been seized to build factories and housing blocks.

Also on Tuesday, crowds damaged a factory run by Turkish textile firm Saygin Dima and the BMET Energy cable plant, which also has Turkish investors, officials from firms in the area said. Both plants are in the Oromiya area.

A third of the Saygin Dima plant in Sebeta, 35 km (20 miles) southwest of Addis Ababa, was destroyed by fire, General Manager Fatih Mehmet Yangin said. "A large crowd attacked the factory," he said, adding three vehicles were also destroyed.

Yangin said a flower farm nearby was also attacked. The Oromiya Regional Administration said vehicles and some machinery at a plant owned by Nigeria's Dangote Cement were vandalised.

Oromiya has been a focus for industrial development that has fuelled Ethiopia's economic growth, but locals say they receive little compensation when land is grabbed. Protests have also increasingly turned to broader issues of political freedom.

The death toll from unrest and clashes between police and demonstrators over the past year or more runs into several hundred, according to opposition estimates. The government says such figures are inflated.

CASTING A SHADOW

The attacks will cast a shadow over Ethiopia's ambition to draw in more investment to industrialise a nation where most people rely on subsistence farming, and have been struggling with a severe drought in the past two years or so.

The government has been building new infrastructure, including an electrified railway connecting the capital of the landlocked nation with a port in neighbouring Djibouti, which was inaugurated on Wednesday.

At least seven foreign-owned flower farms in Ethiopia's Amhara region, another area where protests have flared, were damaged in political violence at the start of September.

The government blames rebel groups and foreign-based dissidents for stoking violence.

Rights groups and opposition politicians accuse the government of excessive force in dealing with demonstrations, crushing opponents and stifling free speech.

The Committee for the Protection of Journalists (CPJ) called on authorities on Tuesday to free Seyoum Teshoume, a blogger critical of the government, who writes for the website Ethiothinktank.com. CPJ said he was reported detained on Oct. 1.

Officials could not immediately be reached for comment, but the government says it only detains people who threaten national security and says it guarantees free speech.

The opposition failed to win a single parliamentary seat in the 2015 election and had just one in the previous parliament.

Rights group Amnesty International demanded an investigation into how security forces handled the weekend protest that led to the stampede during a popular cultural festival in Oromiya, saying it had documented multiple complaints of police using excessive force against largely peaceful protesters. (Additional reporting by Asli Kandemir in Istanbul; Writing by Edmund Blair; Editing by Janet Lawrence)