Taliban militants have killed at least 30 people in a twin bombing near the Afghan parliament in Kabul, injuring more than 70 others, according to the ministry of public health.

The attack during rush hour on Tuesday appeared to have targeted a bus carrying government personnel leaving a building close to the parliament.

The first explosion was triggered by a suicide bomber on foot, followed by a car bomb. An injured security guard told Agence France-Presse the car had been “parked on the other side of the road and flung me back when it detonated”.

The Taliban, which claimed responsibility for the attack, said it had targeted members of the Afghan security forces. But government officials claimed most victims had been civilians.

The interior ministry spokesman Sediq Sediqqi said: “The bus was carrying the administrative staff of the parliament. They were all civilians.”

However, he said a local intelligence chief and four police were among the dead. After the first explosion, police and intelligence officials rushed to the scene, and were then caught in the car bomb blast.

Western security reports appeared to dispute the government claim, indicating that the bus had been carrying intelligence personnel. According to a western official, the local intelligence unit is believed to provide security for the parliament.

A female parliamentarian, Rahima Jami from Herat, was among those injured. It is the third time in recent weeks that an Afghan politician has been hurt in attacks in the capital.

In late December, militants stormed a house in Kabul belonging to a prominent politician from Helmand. A week later, a bomb in the west of Kabul targeted an MP from Bamiyan province.

The latest attack was the bloodiest in the Afghan capital since November, when an alleged Islamic State suicide bomber killed more than 30 worshippers at a mosque.

On Tuesday, another bomb blast occurred at a guesthouse in the provincial governor’s compound in Kandahar, killing between five and eleven people, including several members of the United Arab Emirates diplomatic mission, the governor’s spokesman said.

Fourteen others were wounded, among them the governor, Humayun Azizi, and the ambassador of the United Arab Emirates, who was visiting the province. Kandahar’s police chief, Abdul Raziq, was present at the meeting but unharmed.

In a third incident, the Taliban killed seven people in Lashkar Gah, the capital of Helmand province, in an attack targeting a guesthouse used by intelligence officials.

The southern province has grown increasingly volatile, with the Taliban poised on the edge of the provincial capital.

Last week, US officials announced that about 300 marines would be deployed to Helmand for the first time since 2014. According to the US military in Kabul, the troops are expected to arrive in the spring.