Military forces arrested Sudan’s acting prime minister and senior government officials Monday, disrupted internet access and blocked bridges in the capital Khartoum, the country’s information ministry said, describing the actions as a coup.

In response, thousands flooded the streets of Khartoum and its twin city of Omdurman to protest the apparent military takeover, chanting, “The people are stronger, stronger,” and “Retreat is not an option!” as plumes of smoke from burning tyres filled the street.

Footage shared online showed security forces using tear gas disperse protestors.

A takeover by the military would be a major setback for Sudan, which has grappled with a stop-and-go transition to democracy since long-time ruler Omar al-Bashir was toppled by mass protests two years ago.

The United States and the European Union expressed concern over Monday’s developments.

Jeffrey Feltman, the U.S. special envoy to the Horn of Africa, said Washington was “deeply alarmed” by reports.

Feltman had met with Sudanese officials over the weekend in an effort to resolve a growing dispute between the country’s civilian and military leaders. EU foreign affairs chief Joseph Borrell tweeted that he’s following events with the “utmost concern.”

The first reports about a possible military takeover began trickling out of Sudan before dawn Monday.

By mid-morning, the information ministry confirmed that the prime minister, Abdalla Hamdok, had been arrested and taken to an undisclosed location.

Several senior government figures were also detained, the ministry said in a Facebook post. It said their whereabouts were unknown.

In other hallmarks of a takeover, internet access was widely disrupted and the country’s state news channel played patriotic traditional music.

At one point, military forces stormed the offices of Sudan’s state-run television in Omdurman and detained a number of workers, the information ministry said.

Monday’s apparent takeover came after weeks of rising tensions between Sudan’s civilian and military leaders.

A failed coup attempt in September fractured the country along old lines, pitting more-conservative Islamists who want a military government against those who toppled al-Bashir in protests. In recent days, both camps have taken to the street in demonstrations.

Under Hamdok and the transitional council, Sudan had slowly emerged from years of international pariah status in which it existed under al-Bashir.

The country was removed from the United States’ state supporter of terror list in 2020, opening the door for badly needed international loans and investment. But the country’s economy has struggled with the shock of a number economic reforms called for by international lending institutions.

There have been previous military coups in Sudan since it gained its independence from Britain and Egypt in 1956. Al-Bashir came to power in a 1989 military coup that removed the country’s last elected government.

Among those detained Monday, in addition to Hamdok, were five senior government figures, according to two officials who spoke on condition of anonymity because they were not authorized to share information with the media.

Those detained included Industry Minister Ibrahim al-Sheikh, Information Minister Hamza Baloul, and Mohammed al-Fiky Suliman, member of the country’s ruling transitional body, known as the Sovereign Council, as well as Faisal Mohammed Saleh, a media adviser to Hamdok. Ayman Khalid, governor of the state containing the capital, Khartoum, was also arrested, according to the official Facebook page of his office.