Kabul - Explosions and gunfire echoed through Kabul in two separate Taliban assaults on security buildings on Wednesday, officials said, as the insurgents ramp up attacks before the start of their annual spring offensive.A suicide car bomber struck an Afghan police precinct in western Kabul and a gun battle ensued, the interior ministry said, in what appeared to be a complex insurgent attack.Minutes later a suicide bomber blew himself up while trying to enter the Afghan intelligence agency in eastern Kabul, the ministry added."There were two attacks in Kabul today," ministry spokesperson Najibullah Danish said."There are casualties from the first attack and we also have reports of gunfights, but at this stage we cannot confirm whether it is a complex attack."The Taliban claimed both attacks.The Afghan health ministry said 18 wounded people, some of them seriously, had so far been taken to hospitals."More casualties are expected as the ambulances are on their way," ministry spokesperson Waheed Majroh said.Afghan security forces are battling a resurgent Taliban amid record casualties and mass desertions as the insurgents escalate nationwide attacks even in winter months when the fighting usually wanes.Repeated bids to launch peace negotiations with the Taliban have failed and an intense new fighting season is expected to kick off in the spring.