KABUL - Two suicide attacks in Kabul on Tuesday targeting first Nato then the Afghan spy agency left one person dead and five wounded, officials said, as the Taliban step up their annual summer offensive.

In the first incident, a Taliban suicide car bomber targeting a Nato vehicle rocked the southeast of the city, wounding three people including one described by the police as a “foreigner”.

An hour later three Taliban attackers tried to storm a branch office of the National Directorate of Security (NDS), Afghanistan’s main intelligence agency.

One militant on a motorcycle blew himself up, killing a guard, before other guards killed his two colleagues.

It is the third time in three weeks that the Afghan capital has come under significant attack, and a week ago another Nato convoy was hit by a suicide bomber on the road to the airport.

Nato ended its combat mission in the war-torn country in December, maintaining a smaller residual force for training but leaving Afghan troops and police to face their first “fighting season” battling the Taliban on their own. The Taliban claimed the attacks in messages on their Twitter account. In the wake of the car bomb the street was strewn with rubble and broken glass after the blast, which left a white SUV badly damaged and on fire.

Kabul police spokesman Ebadullah Karimi said two of the three wounded in the first attack were civilians who suffered minor injuries and described the third as a “foreigner”, but there was no confirmation of identity or nationality.

“We can confirm an attack on coalition forces occurred in Kabul at approximately 11:30am,” a spokesperson for the coalition told AFP adding that no foreign forces were killed in the attack.

The second attack, on the spy agency, occurred in the same area of the city.

“One attacker on a motocycle detonated his explosives at the gate of an NDS office, killing a guard and wounding two,” said Abdul Rahman Rahimi Kabul police chief. “The other two attackers who tried to enter the building were killed by other guards.” The toll was confirmed by the NDS in a statement. Tuesday’s violence comes a week after a Taliban suicide car bomber targeted a Nato military convoy on the main road to Kabul airport, killing at least two Afghan civilians and wounding around 17.

A week before that, insurgents launched a brazen attack on the Afghan parliament. Police and soldiers beat back the attack with only two civilians killed,.

But the incident highlighted the Taliban’s continuing ability to strike even at the heart of the heavily-secured capital.

Nato’s combat mission formally ended in December after 13 years, but a small follow-up foreign force named Resolute Support has stayed on to train and support local security forces.

Stretched on multiple fronts and facing record casualties, Afghan forces are struggling to rein in the militants even as the government makes repeated efforts to jump-start peace negotiations.

The Taliban’s annual summer offensive, which began in late April, has sent civilian and military casualties soaring and threatened major cities for the first time in a decade.

A fierce battle has been going on in the northern province of Kunduz, where last month Taliban fighters threatened to overrun their first provincial capital since being toppled from power in 2001.

Meanwhile, two drone strikes targeted militants loyal to Islamic State in Afghanistan on Tuesday, killing between 25 and 49 insurgents, according to differing estimates by Afghan and foreign officials.

An increasing number of militants are pledging allegiance to the Islamic State in Afghanistan, making them a target of deadly strikes there by the US unmanned aircraft.

A total of 49 militants were killed in the strikes in the eastern province of Nangarhar, which targeted the village of Mamd Dara in Achin district, where the fighters routinely held gatherings, a spokesman for the governor said.

“The first drone strike took place at 12 a.m. on Monday... the second one happened at 02:00 p.m,” said Ahmad Zia Abdulzai.

However, the foreign official, who asked not to be named in order to be able to speak freely, said the number of dead was believed to be closer to 25.

One of the most high profile figures to have been targeted in drone strikes so far was former Guantanamo Bay detainee Mullah Abdul Rauf, who had defected to Islamic State and was killed by a strike in southern Helmand province in February.